First off, use the trinket/upgrade it. The two bushes on each side of the lane may not seem like much, but it's definitely worth the little extra gold to drop two wards in there. Even if you only drop your trinket whenever it's off of cooldown, your jungler and support will thank you (one less thing for them to worry about).
Second, if you realize you haven't seen the enemy jungler in a while, you should probably back off and stay near your tower. Chances are they won't try and gank you if you're floating 3 "steps" away from the turret.
Third, if you do get caught out land your E, and a Q and you should be good to go. Worst case use flash. I would save your E for either ganks from your jungler, or as an escape for yourself. I wouldn't use E to clear minions unless you know for a fact where all the enemies are on the map. This shouldn't be that big of a deal since Vel Koz has plenty of wave clear without his E.
Fourth, be aware of the mini map. Please check it every so often, just to see where everyone is. If you see someone getting chased down the river (or vice versa) you can go to help and try to secure a kill. Map awareness is very very very important.
Fifth, just as a general precaution, ping if you can't see your lane opponent. That way other people on your team can be notified before it's too late, they can also come to help if you might be getting ganked.
Sixth, learn how to play more passively, remember, it's not bad to play passively. Instead of you diving too hard/missing an important skillshot, wait for your enemy to make a mistake. Everyone makes mistakes sooner or later. Most players get greedy for a kill and will unnecessarily dive under a turret just for a kill, and usually end up dying and looking like a fool. The only time you should really be pushed to their turret is to either take the turret or push them out of lane/kill them. It's not a bad thing to hug your turret. Some games you just have to let your turret safe guard you. I can honestly tell you the jungler won't want to gank you if you're always staying near your turret.
Keep these things in mind when playing, they can be applied to multiple champions, it's really just a smart way to play in mid lane in general. If you have some type of CC such as a silence, knock-up, stun, etc... try and save that certain ability for when you get ganked. Especially if the ability has a long cooldown. Landing those CC shots can make or break a game.
I hope this helps :)