Half Rite

In ACBL General Convention Chart events (most events) you can employ a half transfer method over your 1C opening:

1D: transfer to Hs
1H: any game force, 1S is now waiting, asks responder to describe game force
1NT: 6-10 balanced, no 4cM
2C: 4+Cs, no 4cM, up to game invite values, may have longer Ds, balanced only if game invite
2D: 6+Ds, no other 4+ suit, less than a game invite
2NT: game invite, balanced with 4/5 Ds
3D: 6+Ds, no other 4+ suit, game invite
Rest: as you currently play it, but 1S natural response is non-forcing

If you want to use the one and only transfer for spades:
1D: transfer to Ss
1H: natural
1S: any game force without a five card major
Rest: as above

After 1C-2C showing 4+Cs, no 4cM, may have longer Ds, balanced only if game invite:

2D: balanced hand with fewer than 4Cs, less than 15, non-forcing
2H: asks for further description, 2S shows unbalanced minimum and 2NT then re-asks
2S: game try in Cs
2NT: 18-19 balanced
3C: to play unless responder is maximum and shapely

If you use 1D as a transfer to spades, you can find heart fits nicely. If you use 1D as a transfer to hearts, you have the nice sequence 1C-1H(any GF);-1S(waiting)-1NT to show a natural game force. When using the 1D as a transfer to hearts, sequences like 1C-1S(natural);-2C-2H are natural and non-forcing, since 1H would be the response with game forcing values. Thus the 1D as a transfer to hearts still allows for most heart fits to be found after the 1S natural response, even without using Reverse Flannery By Responder (i.e. a jump shift over the 1C opening to show 5+Ss, 4+Hs).

Costs to using the half transfer method include giving the opponents new ways into the auction; however the 1C-2D and 1C-3D responses block the opponents far better than the standard 1C-1D response. Likewise 1C-2C is better for obstruction than the standard choices when holding 4Cs and 5+Ds.

Using 1D as a transfer to hearts, 1C-1S is natural and non-forcing, but only should be passed with exactly 3Ss and 11-12 points, since if opener holds extra points and/or 4Ss passing 1S would risk missing a nice game.