Having my characters start to do something has always been a habit of mine, and I know from some comments here that at least some of you suffer from the same thing:
Anton started to climb the hill before noticing that his boots were untied. He started to bend over to tie them when the red-speckled warbler started to call out for its lost young.
For me, having my characters start something comes naturally whenever I include an interruption. The character doesn't have the opportunity to finish whatever it was he or she was doing, so he or she was only able to start to do it.
I don't think this is a major problem, but I find that when I go back and read my prose, the "starts" often feel like extra words.
The solution I've found is that I have to be more precise about the actions my characters carry out. Instead of starting to climb the hill, Anton can step up to the trailhead, or pass the trail marker. In other words, the bigger action of climbing the hill can be broken up into smaller, more specific actions that bypass those sometimes-annoying starts.
In general, sharpening your characters' actions as precisely as you can makes for far more powerful writing.
My favorite painting in the world is Jan Vermeer's "Girl With The Pearl Earring." At first glance, this work might appear to be like any other portrait. After all, it's a depiction of a girl cropped in a rather typical way. But, as we look closer, we notice that the girl is turning back slightly, like she has been caught off guard. Vermeer seems to have crept up on her. A bit of white on her lower lip implies that she was drooling over something, perhaps an erotic thought, something she might be embarrassed about. This painting has not only captured the portrait of a girl, it has captured her in an extremely precise moment in time, and one has the impression that waiting too long or starting too early to paint her would have missed at least some of the information we are able to extract.
As we write, we have the same opportunity to maximally reveal our characters by catching them in perfect spots. It's not enough to have vague ideas of what our characters are doing. We need to focus, study them thoroughly, analyze all of the potential details and record what matters most.