If it's the lotion then I just put on some latex gloves and slater it on my legs before bedtime! It looks like chocolate syrup and doesn't rub into your skin, it kind of sits on top of it.
Don't worry about getting the colour even at this stage, it doesn't affect the end result, just try to get everywhere covered with at least some of the lotion.
Let it dry for as long as possible ( i try to leave it about 20 minutes) before getting dressed, into old baggy pajamas, and go to bed. If any of it does rub off on the bedclothes, it will come out in the wash if you get it washed quickly enough.
In the morning, get in the shower and rub the residue off and you should be left with a nice even colour!
I think it is usually also advisable to exfoliate etc before putting the colour on but I don't bother any more and it doesn't affect the end result!