First thing you need to do is to max out your youth recruitment. This is easier said than done because it depends on your club's reputation. In some saves I've managed to get a steady flow of regens, at least a good one per year (Maybe not a world beater but you could mould them into something useful). In others, particularly in minor countries (Austria for instance), I've never even produced a single good regen in 4-5 seasons due to the fact my club's stature wasn't good enough to go beyond 'average youth recruitment'. *****.
Another thing is to have an extensive scouting network, thus improving your scouting knowledge of the globe. I am not entirely sure if this helps to produce better regens, but it certainly gets you regens from different nationalities - my latest 'creation' being a 3.5 star Antiguan CM.