I look for actual dance steps, rather than them just being used to link various lifts.
I don't like too many lifts, and if they've been included I want to see them done well because so many of the lifts we see are not. I don't like them to interrupt the flow of the dance in any way, and they should fit the music rather than being shoehorned in. They should also be in keeping with the rest of the dance e.g. overhead lifts in ballroom can look messy.
I don't like them to be a 'best of' montage of what the celeb has already learned - it's better to start with the music and work from there like they would do with any other dance.
Showdances I've liked were Louis and Flavia, Alesha and Matt, Matt and Flavia, and Natalie and Artem - all of these dances didn't try to mix too many styles and had a clear structure dictated by the music, with lifts and tricks that added to the performance rather than detracted from it.
I think the ones this year might be alright - Kevin has the right idea to go with a ballroom theme because there have been far too many Latin based messy lift fests. I think Pasha might have finally learned his lesson from how bad his approach was with Chelsee and Kimberley. The other two I'm not sure about but I'm happy to see even one decent attempt at a showdance in a series because we've had so many crappy ones over the years.