When you have dry skin you tend to have quite flaky skin which can also contribute to your foundation not applying smoothly, so I recommend investing in a gentle scrub which can be used daily or around 3 times a week to keep your skin feeling smooth. If you have already done this step and find you still have flaky skin its okay, the scrub wont vanish the fact you have dry skin.
Make sure you also invest in a good moisturiser this helps your foundation apply to your skin well also.
Finally after your skin is prepared you can apply your foundation, I recommend not using a very full coverage or matte foundation as this clings to your dry patches, go for a dewy finish foundation!
The best way I have found is a sponge I have the Real Techniques Sponge with this sponge you have to dampen it so it doesn't soak in your foundation. When applying your foundation you don't want to rub the skin you want to bounce the product onto your skin. This pats down dry skin and doesn't emphasis it.
I hope my tips help you out!
Rebecca<3
