This really depends on what role you're playing.
If you're playing a carry hero, you need to find a way to get your farm to catch up. Kills are ideal, but especially if you're playing solo in match making, it can be difficult to convince people to gank your lane. Make sure that you're good at last hitting heroes and take any kill that you can get.
Ask your supports to start stacking camps for you if you're capable of farming them (gyro, melee hero with battlefury, drow with lifesteal, necrolyte, etc), and stack any camp every chance you get. ALWAYS carry a teleport and use it to maximize your farm. If the game is progressing in such a way that you are able to static farm your lane, DO IT for as long as you can. Static farming is when you do not push your lane, by autoattack denying when necessary and only hitting creeps for the last hit, and the wave just stays where it is. With practice and patience you can do this on command, and it is crucial to playing carry. It allows you to hold the lane somewhere safe (in front of your tower, for instance) and to farm to your heart's content. Circumstances where you cannot static farm are when your other lanes are being pushed--instead of teamfighting and risking death with your team, push your lane back and take the tower trade. When you are behind from a bad start, teamfighting is typically going to make you more behind (depends if you have a teamfight lineup/if you 5 man vs their 3-4man, etc).
When your lane is pushed and your map awareness tells you it isn't safe to farm anymore, go into your jungle (keeping in mind where ganks are likely to come from, and that you are not very safe is your t1/t2 towers are gone that give tp access for your team to your jungle). Look for lanes to tp to and farm. As soon as you see a wave pushing to your tower, tp just before the wave gets there, ensuring you don't give free damage on your tower to the enemy team. And make sure they aren't pushing that, because then you are tping into death.
Support heroes usually get back into the game by ganking. When your tri lane fails, go gank. When you are down 0-5 in the first 5 minutes, go buy a smoke and gank. You need to work on having the awareness of where it is best to gank. Did the enemy team tri lane with their carry and have they been pulling the lane constantly? You probably shouldn't go into their jungle then. What you can do is gank their mid lane. Another option is to single pull a wave in your safe lane, in order to stack your creep waves when the siege comes (3 minutes, 6 minute 30 seconds are the first two). Smoke gank behind their hard laner, kill them, and push that tower. If you succeed you've just got your boots.
Another way to increase your gank success rate is to really work on your awareness. To take away some ambiguity, here are the essential aspects of what I mean when I say "awareness":
1. Using wards in strategic spots+looking at lanes to see what heroes are on map
2. Watching when they go off map and thinking where they are probably going--to pull creeps? to push mid? are they just hiding in fog in their tri lane to try to get a kill when someone goes out of position in their lane? Are they responding to a push in another lane?
3. Check inventories CONSTANTLY. Try to get to the point that even if somebody is walking through ward vision for 2 seconds, you've checked their inventory. Specifically, check for teleports. This is something I feel that I'm very good at--I'm always telling my team if supports have no tps, because it means you can tower dive in your ganks. It also means you can go push towers.
Another useful way to play catchup on support, provided you cannot gank, is to start stacking camps for your carry. When they come and farm it, make sure you are there to get the exp.
Stack->pull your lane and give your starting regen to your carry so they can tank the enemy wave under tower. You both farm this way, while denying exp and gold to the enemy hard laner (but this can be the wrong decision, for instance, if they are pushing your hard lane. Respond by defending if you can or counter pushing if you can't).
And do not repeat mistakes. By this I mean if you go ganking, and your ganks failed, stop trying to gank. If you are tri laning and you keep dying to the enemy tri lane, stop trying to tri lane.
The number one way to catch up as a support hero is to NOT DIE. This should be one of the best skills you have as a support. Can you kite carries really well in fights and pull them so far out of it that it wins your team the fight? Can you position well enough that you soak up damage but never actually die, while getting your spells off? Can you bait yourself well? If you can, you're going to get back in the game simply by the gold that you get for being present.
Playing catch-up in hardlane is similar to that of as a carry. Find a way to find your farm, and stop dying.
If you're mid, ask for ganks, or go ganking yourself. CONTROL THE RUNES. The easiest way to win your mid lane, even against better players, is to have so much mana+hp regen that the skill difference is nullified.
