From what you say above, it seems likely you are selling B2B products/services, not selling to the general public.
In my line of business the organisations I am dealing with are much bigger than me and they have their own T&Cs, which broadly I have to accept or lump it. I read them very carefully before signing the acceptance of their purchase order. If you need to initiate your own, your could spend money on a solicitor or get hold of a purchase order from a similar business, turn it over and read what the typical clauses are and adapt them. It depends how much you know about contract law, I guess.