I've been a drummer since 1978, I've performed live with a click track, and I've switched live TV for over a decade and a half, pushing dozens of buttons on specific cue.
But the playing of WGT can still be a wonderful challenge. 'Timing is everything' is the quote, so my tip I can give to you is try knowing what kind of meter you're dealing with. (See Andyson's post on this, or mine called 'I've made friends with a group of people') But this is only a small part of it...
I always try one swing before I try another and hit it. On the first 'waggle' I set the power and let go and say to softly to myself 'boom' (then the meter gets to just around the ding) and I again say 'bamm'. My brain makes a judgment about how long the time was inbetween 'boom' & 'bamm'.
But my reaction and reflexes vary day to day, maybe I had a beer and while looking at the ding line I click too late so it slices a little past ding. So, next time I'll focus attention a little before ding. 1) If it goes still a little too far right, I'll focus a little more to the left. 2) If I hit too soon I'll move visual focus a little to the right.
For myself, usually, my general visual focus is between the ding and the first line to the left of the ding. (naturally this varies because of different power selections and changing putting increments affect how long the powerbar will travel and also the speed, so I also combine the 'sound timing method' as suggested above. Again, as pointed out, having clubs with common meter speeds is great. I think the NIKE 97 match the Cleves, and the ATVs match the NIKE 85 etc etc. Whatever you decide is up to you.)
Results may vary, and I'm still testing different methods, but I can usually ding a great deal when streaming at 100% CPU usage and that is a real tough rhythm challenge.