first make a list of your potential choices. Clearly some number of ♣ are choices 3♣,4♣,5♣, even 6♣ as is 3♦ (assumes forcing), and finally 3♠ regardless of how you play it then whittle down the choices. 3♣ is probably non forcing, 4♣ is probably only highly invitational, 5♣ is pretty unilateral and may miss a slam, 6♣ is also unilateral and may be too high or too low. 3♦ shows a good suit and for me would be forcing and this would make, again for me, 4♣ forcing it probably will help partner make a better decision after LHO's 4♠s gets passed around to you. Some might play 4♦ as a picture bid with ♣ support. Finally 3♠ could be a LR+ for ♣ or a general GF Qbid and 4♠ a splinter for ♣ one plus of 3♠ is that partner may get a chance to bid 3NT which slows you down since you now have ♠ wastage. This is pretty much a toss up IMO between 3♦ and 3♠