Sniper is a very strong hero, but imho most people plays him too defensive and that is why his true potential is very seldomly comes into play. I put together this build to man sniper up a bit and have been quite succesfull with it both on LAN and online. It requires some skill and most of all some map averness, but even beginners that I played with could use it and become the team carry a sniper should be.
It is quite self explanatory, but the idea is that you put together a shadow boots which gives you good escaping abilities and then you rush for the desolator.
Your 4 tangos should be enough for almost the entire early game and if you have a good support you will never need a helath regen item. If your supports doesn't heal you get a ring of health. You don't really need more than that as when enemy will get to you you will most probably die anyways and will come back fully healed. For minor damages the ring of health will be enough.
Once you have the desolator you will hit like a truck. The whole build depends on your desolator timeing, that is why you should not buy anything else but phase boots and then parts of deso.
Once you have the desolator go for the daedalus. When you have both deso and daedalus you will simply dominate all teamfights! (At this point you can go for speed items to be even more deadly)
The good part in this build is that all items are easy to assemble and take you one step closer to fullfill your role.
Do not buy other items because it will severly delay your desolator and later in the game it will not have nearly as much effect as in early mid game.
Do not buy Shadow Blade! It may save your life a few times but eventually since it is not cost effective damage item it will put you behind and can cost you the game.
Go for the range and head shot all times.
I perefer headshot on level 1 as it will help a bit in last hitting, but if you are against strong ranged heroes (Drow, Viper) you might want to get range first.
Never buy shrapnel! It will just use up all your mana and you will not have it for ultimate. Buy skill points instead. They will give you attack speed, damage, and health instead of the useless spell.
Use your ultimate to secure kills. And nothing else! Never use your ultimate in a team fight as it takes 3 secs to fire. In that 3 secs you aprox shoot 4 times delivering the same amount of damage and 2 mini stuns! The ultimate is to shoot enemies who are about to exit your vision. I have games when I never fire my ultimate...
If you are mid: Play defensively, go only for the last hits to grab your items as fast as you can. Do not try to kill the enemy midlaner as you will probably eat through your tangos really fast if you fight him and you will need to buy more health regen items which will delay your other items. You will be able to take last hits comfortably even if you play defensively. You can out carry your opponent even if you play defensive. Go for the runes but only take them if it is safe to do. Deny them if your opponent is closer. You will get a good laugh out of it and he will go mad :)
If you are in a lane: Sniper is a beast in lane if he is not countered with a strong ranged hero. You can practically zone the enemy out and take all last hits. If you have a support who can heal you you can be agressive. If there is another carry with you let him go first and just mini stun the enemies running away from him.
Mid to late game: If you took an enemy tower (it will happen a lot) go to another lane and start chipping away the tower there. When the game comes to the team fight phase always stay near the strongest carry! Stay right next to him. He will take out the enemies comming for you and while they fight you can dish out the damage. You live and die by him. If you leave him in the fight he will probably die but if you stay you may even team wipe. It only takes a few crits... (desolator + daedalus + crits = 600-800 damage)
With this build you will most probably die a few times. Especially because your enemy will be comming for you. They will realise fast that you are the main damage dealer and will want you out of the fights as soon as possible. That is why it is very important to always have somebody with you. Preferably an Ursa :)
Roshing: When you get your desolator imediately ping Roshan and go with your carry to take him out. You will be surprised how easy/fast it will be
Good against melee heroes, no matter how strong they are. You can demolish Ursas and DKs with this build.
Bad against heroes who can get to you: Anti Mage, Phantom Assasin, Faceless Void etc... Whatch out for any hero that gets blink too
Pudge is a bit of an oddball as he belongs to both cathegory. If you let him hook you he belongs to the bad agianst but he practically never be able to use his ult when you are around. (it is a channeling skill and every 2nd shot you shoot is a ministun) So you can be very good against him
Hope you will have as much fun with this build as I had.
Let me know how it worked for you.
I will update it if anything else comes in my mind.
Thx for reading