Turn off everything you don't need in the wgt game settings is really all you can do. Use the lowest flash setting you can get away with (medium is good for me). Switch browsers also? My settings are below, using Chrome with a decent meter on an ancient PC...........
Display hole in 1 challenges = no
Ball speed boost = N/A (or none)
Use ball speed boost on green? = no
Flash quality = Medium (this is a biggy for bad meters, etc - so they say)
Show WGT lessons = off
Transparent avatar = off
Virtual caddy =show caddy
Distance markers = on
Aerial multi-cam = on
Aim arc = on
Camera pans = on
reflections = off
Putting grid = off
Hole info display = off
Ball trails replay = off
Flag animation = off
End of game messages = off
Putter pal display = on
Shot pal display = on
Show available surveys = no
Show credit offers = no
Pip animation during putt = off
Show swing meter boost = off
Tee shot data = off
Also you can clear your flash with this link: