In any agreement for sale do not fail include few important points like-
i. Time schedule for delivery of possession and penalty in default thereof,
ii. indemnity clause if project is abandoned or defective title is detected
iii. Payment through cheque or online transfer only in lieu of demand letter and issuance of Receipt.
iv. Schedule of payment and default clause on delay in payment.
v. Forfeiture clause on cancellation of agreement.
rests are all usual clauses.