Instructions
Get the kittens checked out by your veterinarian before bringing them home.
Furnish a separate area of your home with bedding, a litter box, toys and food dishes. Place one kitten in this area.
Feed your other kitten near the door to the isolated room where the new one is staying. As they eat on either side of the door, the kittens will be able to smell each other and will associate the smell with one of their favorite things.
Let the kittens play underneath the door. This is a great way for them to get to know each other.
Switch the kittens's bedding to let them get used to each other's smell.
Let the new kitten explore your home and place your other kitten in the isolated room. Again, they can get used to each other's smell and the isolated kitten can get used to your home.
Put up a screen in the doorway to the isolated room. This allows the kittens to see each other, smell each other and play but not touch.
Let the kittens be in the same room for a few minutes. Don't leave them alone. If this goes well, let them play for a few more minutes the next day. Continue adding time until they seem comfortable with each other.
How to Adjust Kittens to Each Other
When you bring home kittens from the same litter, there won't be a problem with their getting along. They'll already be used to each other's smell and be able to play nicely together. However, if you bring home kittens from different litters or adopt a new kitten when you already have one at home, it'll be more difficult for them to adjust. However, since neither is an adult cat, the adjustment period should be short and the chances of problems small.