Both cases are plastered in stickers from various places we've visited. There are stickers on the top, bottom and all sides so we can spot them a mile away and often see them being loaded onto the plane.
I bought two sets of luggage straps from the £1 shop - one multicoloured stripey set and and one green set; and use both sets together so we can pick out our standard black suitcases on the luggage carousel.
We've got bright yellow and green striped luggage straps. I have to tie them on as well as 2 years ago I had mine stolen by someone behind the scenes at either Birmingham or Larnaca airport undoing it, so now with them being tied on, they got no chance. This year I'm also going to use a strap with a combination lock on it too!
Primark have some great luggage tags in at the moment, different colours and designs; and matching passport holders and document wallets too, for the co-ordinated look. I bought some gold/silver luggage tags from there a couple of years ago - another way of making the cases "stand out".
I made my own lables on the computer (before the HT ones were available, will be having one of them this time) with my photo on one side and a bright pink background with my name and email addy (not home address) on the other side. I also have a bright pink ribbon on the handle.