I was the kind of girl that used to put lots of expensive makeup in a little bag and take it everywhere, until they stole my bag with EVERYTHING I had in it. So I learnt my lesson and now I carry essentials and good quality but cheaper products.
I found lots of "dupes" of really good brands:
This is how my makeup bag looks like, basic stuff like Concealers (my under eyes are black ALL THE TIME) so I wear an orange one that neutralizes the color and then one a shade lighter than my skin tone to brighten it, translucent powder with a little brush to set the concealers, my favorite eyebrow pomade but in travel size, tinted Chapstick, highlighter, bronzer, and THE BEST MASCARA EVER.
Of course I switch products all the time, but these have been my go to during summer, lightweight, no foundation or heavy stuff that make me look 'cakey'.