Use selective face priming:
Instead of priming your entire face, try priming only the areas that need it such as your T-zone. Primer actually prevents the skin from breathing by forming a seal over it (much like plastic wrap) so it isn't always the best thing to prime the entire face. Only certain regions may need it.
Don't use sunblock under liquid foundation:
Doing this will make your makeup even more oily and cakey. This also applies to sun serum which I have tried using. Your makeup will get oily much faster if you do this. Instead, opt for using a powder foundation over your sunblock during the hot summer months. I've tried this and found much better results with my skin getting less oily throughout the day! :D
If you must use a liquid foundation, try to get one with SPF in it and use only that without sunblock.
Facial mists are a good alternative to touch up powders:
Facial mists cool down the face and actually refreshes your complexion. Is your face getting overly flushed and oiled down from the heat? Maybe a facial mist is for you! It gives your face a nice refresher without packing on more product and clogging your pores.