copyright when making greetings cards & Pictures

I have recently taken up decouparge (it making cards and pictures by cutting out pictures!), its a hobby of mine. However I am concerned about the copyright laws on gift wrap. Do they apply to a whole sheet of paper or could I cut out sections (e.g flowers etc) and use them without infringing copyright, as I have been recently asked to supply greetings cards that I have made to a store. I do know that I cannot use cartoon people e.g Disney etc.