binders, excipients, lubricants, dyes/colorings and preferably...experience.
You will have to figure out through trial and error how much to use of each to get a good tablet that will hold and not crumble when you pick it up or ship it, or leave them loose in a bottle that might get bumped around or shaken.
Do you know anyone with experience? Much easier to put them into liquid suspensions. But tablets will sell better. That's the only real reason to press your own tablets.
Look for something called ProSolv 50 PRE-MIX. It's an all-in-one. High compressibility. You can use powdered food coloring/cake dyes for your colorings.
You're on your own with the rest.
Keep good notes. You'll figure it out.