I have used lquid latex for various costumes and the like. Imm the only real tips that I can give is to make sure that the area you are applying it to is clean.

Apply some vasalene, lotion or oil first. This helps in removal, if you want to make it easier. Also using water as you remove it works really nice.

Hair and lquid latex don't go very well together. The latex will pull and it is a simmilar sensation to removing a bandaid, over a hairry area, and pulling against the hair.

As for applying it to your pussy, never really haveing done it, I would suggest that you stick to just your outter lips and no real further. If you do you might be picking peices of latex out of there for some time.

As for some finer detail use a smallis brush and do it quickly. Depending on your latex you might no have a lot of time to work with it.