I buy very little when it's only 50% off because I'd like a better bargain than that. Waiting for the discount to be higher usually means that the selection has been picked over BUT that's when you find some of them more random/not so traditional items/colors left on the shelf. This is the perfect time to buy something new and different that you normally wouldn't ever think to buy. People often don't ever think outside the box when decorating. Step out and try something new. You'll find lots of great things to use as a starting point because everyone leaves the more unique items behind.
Here's a perfect example of a great find. A friend invited me to join her on a trip to an outlet mall. She was on a mission to find a new coat so I went along for the ride. We passed by the storefront of Coldwater Creek. This store is primarily a more upscale clothing store for women. We hopped in, hoping she would find a coat. I wasn't aware that they sold much more than clothing but was surprised to find a small shelf that had 50% off Christmas items. Hanging right on the display was a grouping of really cool gold moon and sun ornaments. At half off they were about $1.25 a piece. It was a deal that I couldn't pass up. I usually buy ornament in groups of 3's or 5's but in this case I bought all they had on the shelf.
I'm never in a hurry to take down Christmas each year and I'll often come home after finding some great new clearance ornaments and put a few up them up. One of these moons made it up onto the mantel to enjoy a little time as part of Christmas 2011...LOL
If you're looking for something new to add to your decor for next year then hurry out and start shopping. I got some great deals while out yesterday. Check your local Kohl's...mine had Christmas 75% off yesterday.