A good trick for when you are playing fast is to make sure that your phone's brightness is on full so you can spot the red obstacles against the dark backgrounds easier.
Extra Boosters
Tapping the screen will engage extra boosters but try to only use them when you need to outrun the cops as the extra speed can cause calamitous results.
Orbs
If you do not have the patience to earn cash collecting orbs so you can upgrade you can always spend real cash on in-app purchases to get an instant headstart on the leaderboards.