Ok, I tried to think of a creative post title but obviously that didn't work out. Oh well. Moving on.
As far as makeup goes, foundation is one thing I don't own a ton of. While some things (eyeshadow, blushes) don't go bad, there's a time limit on foundation so I'm not going to buy 10 different kinds for the sake of having a variety of coverages if I'll end up having to throw most of them out. And it turns out, you don't need many.
When we went to Vegas, I didn't want to take my regular foundation and my tinted moisturizer although I knew I'd want both. I ended up taking the regular so I'd have that for night, then during the day I just mixed in a little of my regular moisturizer with it to lighten the coverage. It took 2 seconds and saved me from having to pack another item.
I kept experimenting with this once we got home. Regular liquid foundation has a medium to full coverage and tinted moisturizer has a light coverage, so to get anything in between just mix them however you want. It's seems so obvious, I'm not sure why I never though of it before. I love it though because with your 2 foundations (or one, if you want to just use regular and everyday moisturizer like I did at first) you end up with a ton of variety. Much more wallet friendly then going out and buying a new foundation :)