Many members join because they are planning or already have a new parrotlet, here are some tips in making your new bird more comfortable in his/her home. These tips are generalities with a focus on a baby parrotlets; each parrotlet is different, with different personalities, so they may not all apply to yours.
1. When a parrotlet goes into a new home, remember that his world has changed completely. He's no longer with his breeder (the familiar human) or with his clutch mates. A parrotlet may be social and more interactive in the original home (whether breeder, first home, pet shop), but become timid in a new home. Give him time to settle in the new home first. It may take just couple minutes, it may take days to months.
2. It's recommended that millet should always be available in the first month of being in a new home, especially baby birds. A lot of birds are weaned on millet and others will treat it as comfort food, eating it solely because they're stressed.
3. Unless you are getting an unweaned parrotlet (which recommendations are not too unless you're an experienced hand feeder), most parrotlets will wean sometime between 6-12 weeks of age. There is a big variance in ages, because each individual will wean at different times, even within the same clutch. To try to limit regression issues, the best time to take a parrotlet home is 1 week after being weaned and eating food on his own.
4. Regression is a term that is used for a baby parrot that was weaned at the breeder's and then become stressed and wants to be handfed again. A parrotlet will show signs of regression by begging for food. There may be crying/chirping for food, head bobbing, losing weight, and no food eaten on his own. If this happens, either you should start hand feeding if you know how or bring the parrotlet back to the breeder to have them hand feed again.
5. Gram scale. Ideally, you should have a gram scale at home to weigh the parrotlet's weight. Parrotlets in general (also depending on species of parrotlets) will weigh 28-35 grams. The ideal time to weigh them is first thing in the morning before they've eaten, as this will eliminate the problem of food weight that may be in the crop which can vary day to day. The best way to determine if a parrotlet is losing weight is by weighing them daily when they first come home and watching their weight trends. A parrotlet that just weaned may lose some weight initially due to the transition from formula to seed or pellets, but should regain it back. Anything greater than 1 gram of weight loss is considered to be a potential issue.
A gram scale is additionally important even though you think your parrotlet is eating, because sometimes they're playing with their food and not actually eating. If feeding seeds or millet, you should see empty seed hulls around the cage; but even that may not be enough as they may be eating a little bit, but not enough to survive. There have been many young birds who have done this and died from starvation.
Parrotlets tend to have high metabolisms and will eat a lot, especially for a bird of such small stature. Additionally, a good sign of them eating well is pooping well. Most parrotlets will poop about every 20 minutes. The poop is the darker portion of the material that comes out, the white portion is the urine. If you notice that the darker portion seems to be getting smaller, your bird may not be eating enough.
6. Bowls of food and water should be similar to those at the previous home and placed in the same area as the previous home to ensure that they know what and where they are. Many breeders will place bowls down low or on the floor of the cage for babies, so you may want to do this first to ensure that they know where the food and water is.
Something to consider is covered dishes. If the previous home did not have them, new parrotlets may not realize that they contain food and water or know how to navigate them to get to the food/water.
You may also consider putting food/water dishes up high as parrotlets will naturally want to perch on the higher perches. And when stressed in a new home, may not be willing to go to the bottom of the cage to eat and drink.
7. It's recommended that you feed the same or a very similar food as the previous home to make the transition to the new home easier. Some birds are pickier than others.
At the same time, you can also offer new stuff, fresh foods, etc. This will allow them to get used to the presence of it even though they may not try to eat it yet.
8. You should have your parrotlet examined by an avian veterinarian soon after bringing your baby home. This will help ensure that you have a healthy baby. Some veterinarians will recommend bloodwork and/or poop check to ensure your parrotlet is healthy.
9. If there are other parrots in your home, the new parrotlet should be quarantined from the other parrots for 30-60 days. Usually a new parrot will be stressed going to a new home and this is the time period where they will come down with an illness. The quarantine will help ensure that the other parrots in the home are not affected.
Ideally a quarantine would entail the new addition being housed in a different room (completely different air supply would be ideal but usually impossible in most cases) and the new parrotlet would not have any contact with the other birds.
10. Cage set-up. A young baby parrotlet will tend to be clumsy when young. A smaller cage is usually preferred until they're more stable. The perches should be placed lower in the cage and you may want to consider padding the bottom of the cage with a towel in case they fall.
Otherwise, the general rule of thumb for the preferred cage size for a parrotlet is as big as you can afford and put in your home. Many members on the forum prefer flight cages. Most parrotlets are very active and will use just about every inch of their cage.
When buying a cage, make sure that the bar spacing is at maximum 1/2 inch. Anything bigger than that, you're parrotlet may be able to squeeze their head through the bars. Additionally if you have doors (usually it's the food/water bowl doors) that slide up and down, you may want to clip them shut. Parrotlets have been known to try to escape through these doors by sliding them up.
11. Training: the key is patience. As soon as you think your parrotlet is ready, you can begin training him. The time frame will vary from parrotlet to parrotlet. Some parrotlets are ready as soon as they get home, others prefer to settle in the new home first. Go at the pace that your parrotlet is willing to go. If they act scared, go more slowly. If they're eager, then keep on training. Usually, I recommend 5-10 minutes of training multiple times throughout the day. You can only expect a parrotlet to step up or do tricks so many times before they get bored! If you need a more detailed information, check this thread: https://talkparrotlets.com/showthread.php?t=4603
12. To trim wings or not. This is personal preference and you should make your own decision. But in general, I think it's easier to train a parrotlet when their wings are trimmed. This allows the bond to happen more easily as you don't have to chase them around (which can sometimes mimic a predator). After that you can let the feathers grow back and see if that's what you prefer. Just keep in mind that you should try to keep your home as bird safe as possible if you have a fully flighted parrotlet (no cooking when he's out, no ceiling fans on, etc).
13. Biting. Please refer to the Gentle Beak technique sticky here: https://talkparrotlets.com/showthread.php?t=12871
14. Signs to watch for if you think your bird is ill: any behavior changes, puffed up feathers, tail bobbing/heavy breathing, not eating, half closed eyes for a lot of the time, sleeping a lot, sleeping on the bottom of the cage (especially if they didn't before), wetness around the nose, poop sticking to the butt, diarrhea, weight loss, etc.
If you notice anything that may make you think your parrotlet is ill, please take them to a veterinarian immediately. Unfortunately, even if you post something on the forum, we may not be able to tell you accurately what to do or respond in a timely manner.