What make-up should I use to hide my freckles?

That really depends on just how “prominent” your freckles are. If you have the kinds of freckling that is a widespread spray of freckles that are just a little darker than your skin tone, you may want to use a tinted moisturizer and loose powder to cover and blend away the freckles for an even skin tone. However, darker, high-contrast freckles may need an oil-based liquid or pressed powder foundation in order to cover them up and give you smooth, even skin.
 
The thing to remember is that you want to match your base skin tone carefully. You will only defeat the purpose of the make-up’s use if you use a foundation color that is darker than your skin’s base tone in order to better cover-up the freckles. Wide-spread dark freckles can be dotted with concealer before applying the foundation to make coverage easier.