I have rosacea on my cheeks/large pores. and dry skin on my forehead. I need a concelear and a foundation that will cover up rosacea and make me just look natural but that will last all day.
You should use a moisturizer on the dry areas of your face before you begin applying any makeup.
You should try a good foundation primer such as NARS Skin Smoothing Face Prep which prepares your skin for a flawless makeup application. Designed for trouble spots (fine lines, large pores, rough spots, and other imperfections), this formula creates a smoother and more even canvas for your foundation application. It creates a matte finish that leaves your skin feeling comfortable, not dry and you can find it at: http://sephora.com/browse/product.jhtml?id=P261210
A great concealer is Make Up For Ever Full Cover Concealer which is an ultra long-lasting, matte finish, oil-free, waterproof, full coverage concealer. You can find it at: http://sephora.com/browse/product.jhtml?id=P151107
A great foundation that is designed for skins with mild to moderate rosacea, and for dry, dry-combination, or oily-combination skin types is Clinique Redness Solutions Makeup SPF 15 which you can find at: http://sephora.com/browse/product.jhtml?id=P271903
I hope this helps you.
It sounds to me like you are going to have to get into the habit of sort of spot priming your face. I'll explain in a sec but just first let me say that you should never really use foundation to "hide" anything on your face or you will most likely end up using too much. Foundation really shoud be used to just even out your skin.
the best thing to cover up the redness in your cheeks is not really a foundation but a color-correcting primer. however since you also have an issues with large pores I suggest you go in with Benefits porefessional first, http://www.sephora.com/browse/product.jhtml?id=P26
Then, go in with your color correcting primer like Smashbox's green primer if you have oily cheeks, http://www.sephora.com/browse/product.jhtml?id=P78
Or if you want something more emollient, you can try this one from Clinique, which if you're in a cold climate is particularly soothing, http://www.sephora.com/browse/product.jhtml;jsessi
I think if you go in with your foundation and concealer after this you will not only use less but you will get a smooth, even finish. If you don't have any other skin issues (like acne) then perhaps even a tinted moisturizer and a good concealer will work.
Hope that helps!