We cook New Orleans style red beans from scratch on a regular basis, but for baked beans (which we also like very much), we buy canned beans and dress 'em up. (I think that, years ago, my wife would occasionally buy dried white navy beans and try to produce Boston-style baked beans from scratch, but the results were never worth the extra effort.)

Here's our current approach, as followed for at least the last 20-25 years:

We dump a large can of the current-favorite brand of canned baked-beans into a deep casserole dish, stir in generous quantities of mustard and molasses, float a skillet-load of carmelized onions on top, and stick it in the oven for a while. Always a big hit.