The old push/pull/leg routine can work.
chest/shoulders/triceps
back/biceps
legs
off
You can work these in any order, just be sure you have a day off or two a week. You may not want to do as much volume as you would with a 5 day split, but you still need to work with intensity. Recovery time and nutrition will determine your results.
Well said and all things being equal this routine will yield solid results for quite some time. Just make sure you eat and rest!