Hey There,
When I have my hair in a weave I usually moisturize everyday (when I'm a good girl and remember to that is
) with a light water based leave in moisturizing conditioner. Aphoogee Pro Vitamin Leave in Conditioner is a great one to use while in weaves. Another great one is Neutrogena Tripple Moisture Silk Touch Leave in. This one is a little thicker and so I water it down and shake it up before I use it.
The reason why you want to use something with a lighter consistency is because your hair is all braided up and 1) A liquid with a lighter consistency can seep through the braids instead of just sitting on top of a braid or the scalp and 2) Frankly, the thicker the consistency of the product the more likely you are to have product build-up.
I apply the product either in an applicator bottle or a spray bottle (whichever I can get my hands on at that moment..) and I just apply/spray at the base, into the braids. Granted it's hard to keep the rest of the weave hair from getting wet but if you're very precise you won't get the whole thing wet. I also wash with a moisturizing conditioner such as cream of nature detangling and moisturizing shampoo every week. It's much easier when the hair you use is curly because you can wet the hair and let it air dry...
Hope this helps...