I use my Tesco credit card for everything I possibly can - even some regular bills.
I pay it off in full every month - meaning my money is earning interest in my current account AND I get over �300 worth of Tesco vouchers each year.
There are advantages to buying goods with credit cards - the main one being that if the goods are faulty or not as described, I can recover the money from the credit card company if I can't get it back from the trader - s.75 Consumer Credit Act (providing goods cost over �100). It is essential to pay for major purchases, flights and holidays with a credit card for this extra protection.
I would never use credit card cheques - they are expensive! Interest starts accruing immediately and there is a fee attached, and s.75 does not apply.