What everyone has said is right, but it's especially important in Crystal because there is relatively little experience in the game and most Pokemon have barren movepools.
It's best to look up the movepools and decide for yourself. Doduo evolves on 31, but learns Drill Peck at 33 (Dodrio learns it at 38). I'd hold off for that. I wouldn't wait until level 46 to evolve my Mareep (Thunder), because it has access to weaker electric moves that will do the job, and the Pokemon will actually be usable.
I know people who will breed egg moves onto Pokemon in Gen II because level up sets are so bad. Exeggcute doesn't get any grass moves until level 43, the Eevee you get from Bill is already too high a level to get the level 16 STAB move so it won't get anything until 36 instead etc.
>>37593195>>37593201Most stone evolutions are only available late game anyway.
