Quite a few of these off flavors can be acquired by abusing your beer.
F.e. take two bottles of fresh beer. Store one as you would your most prized homebrews. Lug tyhe other along with you wherever you go for the next couple of weeks. Car rides, bike trips, take it on a jogging runs, juggle it, place it behind a window in the full summer glare,.....
Dr.Beer used to be up and have plenty of such beery excercises, but with a bit of inventiveness, they're easy to figure out by yourself.