What kind of skincare products are you using?
It is important to understand that the oil absorbing properties of the products such as foundation and primer are limited - they cannot absorb loads and loads of oil all day, but they will be able to absorb a certain amount before the oil becomes visible.
I have oily, dehydrated skin which is prone to spots. So I try to avoid certain things as they tend to make me break out. I like when my skin gets a more natural finish (not keen on completely matte), so I tend to only touch up the makeup once or twice a day.
I use the gentle cleanser from Shiseido's Ibuki range - I got a sample of it and it just worked for me. It cleanses my skin without stripping it of moisture so my skin doesn't feel tight and horrible after.
I generally don't use moisturisers as they tend to break me out or make my skin terribly oily. Instead I just use a serum. With my skin being oily and dehydrated, I need hydration in form of water, not oil.
I've been really happy with Aesop Parsley Seed Serum (which is quite expensive, but I've used this every single day for 8 months and the bottle is a little more than half full still.
The Shiseido Ibuki range also works for me - there's a serum and a moisturiser and using them together works great for me.
Indeed Labs Hydraluron serum (Boots has it) also works well for me - I have the moisturiser (moisture jelly) and it's a tad too rich for me.
Generally, anything that's hydrating works for me.
For makeup removal I use Clinique Take the Day off Cleansing Balm - it doesn't leave a residue and doesn't break me out, but removes my makeup really easily.
I'm not a massive fan of primers and often, I'll skip them. But I have been using the green Smashbox one for years. The Maybelline Baby Skin one is similar (just clear). If I'm not completely wrong, Laura Mercier has one that feels very similar that can be used on top of makeup for touch ups - I wouldn't be surprised if the clear Baby Skin or Smashbox ones can be used in the same way.
Benefit Porefessional doesn't work for me at all.
For foundations, I like Laura Mercier oil free tinted moisturiser - it's a light coverage foundation.
EL DWL works really well for me.
Diorskin Nude is great - it's light/medium coverage and looks great.
I'm not a fan of Clarins Everlasting foundation - it's too heavy and during the day, it gets cakey and doesn't wear well. The sample I had was great, but when I bought the bottle, it was horrible.
BareMinerals BareSkin isn't great either - it settles in lines and dry bits of skin and just doesn't look right.
How the foundation is applied also seems to be relevant - I find that using a good brush like a Buffing Brush or Expert Face Brush (from Real Techniques) makes my makeup look better and last longer than if I've applied with fingers or a paddle brush.
I set my foundation with powder - I like Mac Mineralize skinfinish natural a lot, but I have other powders that work as well.
I always have a Mac Select Sheer Pressed Powder with me for touch ups.