1. Invest in expensive paints
Oil paints can be expensive, but it’s definitely worth investing in some expensive ones. Generally speaking, the more expensive they are, the higher the quality. By all means, if you’re doing several under layers, get these done first using a cheaper oil paint; then simply save the most expensive paints for the topmost layer.
2. Don’t use acrylics on top of layers of oil paint
One of the main properties of oil paint is that it’s incredibly slow to dry. In fact, it can be notoriously slow to dry. With this in mind, you shouldn’t use another type of paint, such as acrylic, on top of oils. Acrylics, for example, are very quick to dry. If you apply a layer of acrylic on top of a layer of oil paint, the layer of acrylic will eventually crack or flake due to the oil paint taking a lot longer to dry out.
3. Try using acrylic paint for bottom layers of the painting
Conversely, you could try using acrylic paint for the bottom layers of the painting.