1. Use A Makeup Setting Spray. 
2. Blend The Foundation Well. 
3. Hydrate Your Under-Eye Area. 
4. Dab Off The Excess. 
5. Use A Face Oil. 
6. Use A Setting Powder For Oily Skin. 
7. Avoid Applying Too Much Makeup On Creased Areas. 
8. Apply Eyeshadow Primer On Creased Areas.

Another way to help smooth out cakey foundation especially if you have oily skin is replace primer, use your damp blending sponge to apply a finely milled translucent setting powder on areas that get extra oily, like your T-zone. Let it sit for a few minutes, then brush off the excess. Continue with the rest of your routine foundation, concealer, etc

If your foundation looks cakey, there's probably a simple reason. One of the main culprits of this makeup mishap is none other than applying too much product. ... Other reasons for cakey foundation include dry skin, not layering your makeup correctly, and not using the right skin care products.

If your foundation goes patchy , you don't apply primer before your foundation
Primer acts as a barrier between skin and makeup, so if you're oily it will stop the oil from seeping through and making make-up slide. “And if you're dry, it will stop your skin from almost 'drinking' the foundation which can make skin look patchy and uneven.