I use 'drafting'. The only circumstances where I have seen 'draught' used are either in reference to windiness or a draughting table. Either way, I have not seen the verb form used in quite some time.
The OED seems to agree that 'to draught' is rarely used, even in British English:
"Even in British English, use of the spelling draught is now rare, although it is still occasionally found, chiefly in [the verb form]. The loss of the spelling distinction in the verb (but not the noun) probably results from the fact that the senses of the verb in which draught might have been preferred are much less common than the others." [emphasis added]
As the OED says, 'to draught' is occasionally still used. A recent example can be found in a piece in The Guardian from 2014:
""My partners all draw like a dream," grins Rogers, who is open about his dyslexia and poor draughting skills..."
In sum, it is perfectly legitimate to use 'to draught'. However, it is highly uncommon.
