You don't just ward to protect yourself that is only half of what wards do for you mid. If you put your wards deeper into their wraith camps and the wolf bush and get vision of their jungle entrances it provides you with something much much greater than safety, vision of the enemy teams rotations (and most of the time you'll be able to keep track of the junglers position and health for a possible easy kill). This lets you see if the jungler is heading to do wolves you can possible snag their wraits, and if the mid lane is doing wraiths you know they aren't roaming for a kill so you can just do your wraiths, counter them at their wraits, or go for a free gank yourself. It lets you counter roam, counter jungle, call effectively which side of lane your mid lane left. Theres just so much you can do with wards, and then if you can do that much with them think about your opponent, if he's good enough then buying pink wards will shut down all these gateways for him to abuse.
Learn Your Counters
Everyone has a champion pool: Champions they know how to play reliably enough to be used for serious business games. It’s larger for some people than others, but part of building your champion pool is learning their strong and weak matchups. For instance, Katarina is a strong mid champion but will get crushed if paired up against a Galio or Kassidin. Don’t just learn the counters, understand why they are counters.
Counter Pick Your Opponent (But Do So Intelligently)
If you know who your mid lane opponent will be, picking a hard counter will give you a massive advantage in the laning phase. LoL Counter is a great quick reference guide to this. However, a common mistake I see in Bronze is players blindly following such websites and picking champions they have no experience with, expecting the “counter” to magically win them the lane. In practice, this will cost you games. You want to pick the best possible counter that you play well. Remember, the best counter to your opponent is always outplaying them.
Don’t Be Afraid to Adapt Your Build
Especially early on, prepare you build for the lane you expect to face. If you’re going against a skillshot-heavy champion, boots may allow you to dodge more damage than a few more pots would allow you to heal. On the other hand, if your opponent has easy-to-apply harass like Malzahar or Vladimir, more health pots will allow you resist their harass for as long as possible. Continue this mentality as the game goes on. You should have your build planned out and practiced, but don’t be afraid to adapt to the game as it unfolds.
Mix Farm with Harass
Your primary goal in lane is to get as many last hits on minions as you can. Crushing the farm and crushing your lane frequently go hand in hand. Don’t neglect the other part of laning, though: forcing your opponent off their own farm. This is harder to do with some champions than others, and counter picking as well as jungle pressure will play into it, but generally speaking when you aren’t last hitting you should be harassing or zoning your opponent.
There are 2 side bushes in the midlane and you need to ward the shit out of them. If you buy all health pots to start, throw 2 wards in the mix. If not, which is usually the case, start buying them on your first trip back. Place them as deep into the river as you dare, but at least make sure you get vision inside the bushes, if not the paths to them. While not foolproof, they will protect you from a lot of jungle ganks and are well worth the price.
Leave Enough Mana To Escape
Obviously this tip only applies to mana-based champions, but it’s an important one. Many champions have an escape move of some kind, whether it’s a dash, flash, wall, or simply some way to crowd control people which you can use defensively to keep them away from you. Using abilities to harass and farm is fine, but always keep enough mana to activate your escape ability.
Coordinate With Your Jungler
As a midlane, you will commonly have a crowd control effect of some kind; hopefully a stun, root, or heavy slow. Communication between you and your jungler is very important. If you lead with your stun ability, the jungler will have a higher success rate closing the gap and securing the kill. Dead enemies can’t farm, and many midlane champions can snowball such advantages very easily.
Push Them To Their Turret; Practice Last Hitting Under Yours
If things are going well, you will push the enemy champion back enough that they aren’t hitting your minions and the minion wave is beginning to get hit by their turret. Minions killed by turrets provide no gold and last hitting minions under one’s turret is tricky business. If things aren’t going well, then you’re learning about that first hand. Try to get your enemy into this position, and practice last hitting under a turret on your own to minimize the effect of being in that position yourself.
Wraiths and Wolves
If you’ve pushed the minions to the enemy turret, the farm doesn’t stop there! Rather than hang around near their turret in a vulnerable position, back off to your wraith or wolf jungle camps and farm them. When done, return to the lane, last hit all the minions, push the enemy back to their turret, go farm another jungle camp. If you’re feeling very daring and/or know where their jungler is, you can farm out the enemy wraiths to do a little counter jungling.
Call MIAs and Roam
If you lose vision of your opponent, let your team know right away. This is doubly true if you’re under your own turret. Why? Aside from farming jungle camps, another great gold generating option for when your lane is pushed to the enemy turret is roaming to side lanes and getting a kill. If you’ve pushed the minions to the enemy turret, this is a great option for you as well, especially if your champion is fast or has teleport. Because it will take time to travel, I only recommend doing this to gank enemy laners that are grossly over extended. Teleport ganks setup by wards in bushes behind the enemy give you a little more leeway on this and thus more opportunities. If you don’t see a good ganking opportunity, default to farming the jungle and then going back to lane. When you’ve pushed your lane again, take another look. Rinse, repeat.