Sniping can gain you top score in games where all buildings are destroyed or when time runs out. The money is in killing characters that cost 500 credits and upwards, where as regular engineers net you nearly nothing. It may be fun to sniper engineers but for your hard work in supporting your team on the battlefield you won't get many points out of it.For Nod, being a sniper contains no paranoia factor as you can have free reign over the entire map while your team can give you little, to no support.. or to having the map dominated.
For GDI you have the paranoia factor. Your team needs to dominate the field and you cannot risk having a getaway vehicle nearby. A good Stealth black hand will murder you, or a tank of any sort blow your head in with a single tank shot.
Avoid uphill targeting if in third person if you can. If good enough, safe guard key areas and be escort to a demolitions team.
The best tip of all, learn to fire without scoping out at all ranges so on instinct you fire when your crosshair just is about to turn red. The best snipers after all dont need to scope out and diminish their peripheral vision.
Of course the last second scope out and shot to the head is the most important tactic when taking advantage of third person perspective behind cover and running out to make a kill.
If there are many people repairing their vehicle in the open, they are lamerz. Kill them and then find a server with good players. Of course Nod has less a paranoia factor when it comes to repairing out in the boonies especially if they have good sniper defense/offense.
On very wide open maps, if you see a hummer or buggy coming, just unload like crazy on it if you feel safe from reprisal, you'll likely get it down to half, then let the tower rip it apart or your team mates.
If you snipe 10 people in a game, thats good, keep practicing... don't blame it on lag.. cuz you suck if you can't handle a 400 ping and snipe someone in the head... don't complain... thats what noobz do.
If you snipe up to 30, you are an elite sniper and the other team has just gotten careless because they fear you. Find yourself a good clan.
If you snipe 60+ people in a game you are awp god and are probably having a very good day and just had sexual relations with a hot looking chick and you should try out for a very good clan so as to make proper use of your murderous talents.
If you are killed many times over by the uber elite sniper corp of Renegade, switch to another class which will help your team out, because getting 10 characters at about 5000 to 10000 credits popped in the head is not helping them. Go buy flame tanks or stealths or mammoths or train for beacon runs. Remember... there is always someone better then you and team work does make your skills even more incredible and invaluable to your team.
If your uber elite skill is high enough, use the weak sniper with silent rifle. Purchase Sakura or Havoc only if you want to be able to take more damage, and/or want the extra damage vs infantry and vehicles.
The best training to become a great sniper is Deadeye or Black Hand. Range in meaningless, shoot for the head.