I blend beers of the same style together by combining kegs. For example, I will make two to 3 single hop beers at a time (same wort) and do a hopstand and once I'm getting low I will combine the kegs and get a new beer. I try blending the different beers in a glass just to make sure that'll work out first.
I tend to blend beers of different styles in my glass for fun, for exploration, because I want to drink a RIS but want a lower alchohol content, etc.