For the most part, people don't know if they're gonna feed before hero selection. However, if you do, you need to pick the right heroes.
IO (His low hp combined with an ulti that allows him to teleport are ideal of quickly feeding you AND a teammate. Teleporting that shitalker to an unreachable location and not allowing the courier there helps inflicts unintentional abandons)
Nature's Prophet's teleport allows for more frequent feeds in addition to his q which will allow you to strategically trap a teammate. Even your treants can provide some extra cash for the enemy. Be sure to try to blend them in with other trees for added fun.
Faceless Void (A well placed chrononosphere can help save the enemy from a gank)~
Spirit Breaker (Charge in then do nothing, has the drawback of providing some vision on the enemy)~
Leshrac because even when you're to play him normal you're probably gonna feed
Now lets say you didn't know you were gonna feed before hero selection. You still can throw the game if you do it right. This means building the right items on your hero.
Buy the courier first, dont activate it, later feed it along with others IN FORMATION only.
Buy up observer wards as soon as they are available (place them strategically around the ancient) Feed it in the courier, or let the enemy see you place them and provide them sentries so they have more gold, or give to the enemy directly
Boots of Travel are a must for that added speed.
Force staff allows you to take your teammate out of position, ensuring more feeding.
Armlet allows for faster hp drain, make sure not to accidentally target the enemy.
Mask of Madness for that extra jolt of speed and hp drain.
Blink Dagger: more speed for that feed
Drum of Endurance: Hahha more feed speed Too much health boost, not enough speed. Use the extra gold for spelling out curse words with the sentries and interesting courier formations.
Gem of True sight: Give that enemy some free vision, when needed
In terms of gameplay, you do not just run around mid and feed. This only allows one player to get fat. You want to go bot and top and even alert the other team to your incoming presence and intention. Communication is important , for the other team. You gotta let them know when your team is going to rosh or is in smoke or all rotating to another location. Wait who am I kidding, no one ever uses the fucken smoke.
When you are properly feeding, you need to hit the enemy before letting them slay you. This may be counter intuitive but I have avoided being punished from feeding many times by hitting the enemy before dying. That way it looks like you tried to fight, it makes a harder case for the intentional to stick.
In some situations you will need to feed harder than other times. The other team is just so freaken bad that the 20 kills u fed them just aren't helping. This is when you send in the army of couriers. This provides much needed gold for the enemy. Make sure the enemy is supplied with gems if they need it and make sure you are distracting you teammates with insults and intercepting their courier.
With a lil practice and effort, you will make those "teammates" rue the day they rightfully called you a noob.
Edit: Apparently I can't even make a comprehensive guide on how to feed. I see some great hero recommendations and some great strats so I'm gonna copypasta integrate that below.
Additional Hero Selections:
Tiny (Tossing teammates into danger and it can't even be disabled!)
Tusk: Do you wanna build a snowman? Come on lets go get slayed!
OD/ Shadow Demon ( They'll never escape that gank thanks to that imprisonment)
Chan ( Teleport them back to base, it'll definately test their faith in having patience)
Kunkka ( Cast X marks the spot on teleporting teammates and watch the confusion and rage unfold)
Pudge ( Pull your teammates over to the other side of the river and be sure to body block, or trap em on a cliff)
Venge ( Put yourself into position to be ganked the swap out and watch them get ganked instead. Be sure not to level up the aura)
KOTL ( Bring that shittalker to come ganked with you.)
Earthshaker ( Block your cowardly teammates from escaping with a well placed fissure; a great pick up vs anti mage)
Earth Spirit: Kick/pull allies into enemies/onto cliffs. Buy a scepter for bonus points! And really, you are just as bad with him as you are with leshrac so even when you're trying your dying.
Oracle : If you see that the enemy team has heroes like PA and Juggernaut, Oracle is a great pick. When you see PA/Juggernaut jump an ally, quickly cast Purifying flames followed by Fate's edict on the ally. Don't forget to flame your ally in allchat right after that. Plus Oracle is really squishy so you die really fast too!
Winter Wyvern: Stop! In the name of hate before they break your heart.
Naga Siren: Ruin those FV and Enigma ultis with the naga song.
Legion Commander and die in duel every time its up.
Lone Druid: Fill up that bear with some couriers or wards or a gem and make a special delivery to the enemy. Don't forget to let the enemy know that he's friendly and comes bearing presents. They'll love petting him.
Morphling mid and go full agility.
Tinker : With rearm you will be the fastest feeder ever. No CD on teleport!! As a bonus, you can also steal farm!
Terrorblade: Activate your armlet and then ulti a weak enemy to grant them full life.
Techies: Just picking him will inflict massive damage on the team psyche. Then steal some farm with your mines and its a recipe for starving and frustrating the carry. Apparently, placing mines at the jungle creeps can block the camp. God I'm such a noob.
Situational:
Divine Rapier (Does the enemy have someone who actually looks competent? Make him fatter than pudge on Thanksgiving by feeding him the rapier. Could end up throwing the game in your teams favor so use with caution.
Hand of Midas (If you have no exp/gold, the enemy benefits less from killing you every time. This allows your feed to stay relevant even till the mid-late game.
Euls (Save the enemy from that op ulti)
Necronomicon (When the enemy needs that extra boost of gold).
The Aegis, if your team is able to rosh make sure you're there to snag it. Guaranteed to make the Ursa on your team curse in Russian.
Psychologically:
Laugh annoyingly into the mic, ask your team to commend you for ending the game quick, and tell them to relax because it's just a game. The chat wheel is also a fun way to be passive aggressive. Spamming well played! after every death is a must. Adding players is a possibility if they let you, there you can spam voice chat and gift them common items with mean inscriptions. Its also a good way to laugh at their mmr if its lower than yours or call them a tryhard gaming nerd if its higher.
SOURCE:
http://en.reddit.com/r/DotA2/comments/2yui1o/a_feeders_guide_to_feeding_or_how_i_ended_up_with/
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