They take soooooo long to dry
Well that is a problem and blessing too....a blessing because it allows you time to work with the paint or strip it off, unlike acrylics that dry so fast.
I've learned three tricks that speed up drying....1) and this is important...you squeeze the paint onto a piece of card, like an index card or a piece cut from a cereal box, the card absorbs some of the oil in the paint...(2) once you squeeze the paint onto the card, walk away for 10-15 minutes, that allows more of the oil to be absorbed and some to even evaporate into the air.....both these two things really help the drying time. (3) I put my model into the oven with no heat but the oven light on between painting sessions, usually 4-6 hours or even overnight...that really speeds up the drying.