A few counselor tips from me:
1) At the start of the game, most people who play as Jason will pick up the knives in his shack before morphing on the map. There will then be a further 10 seconds or so before Jason gets his sense ability. As a counselor, this means you'll generally get at least ten seconds until you'll even have a chance of seeing Jason, and very often 10 more seconds before he'll having a chance of sensing you. Use the first 20-30 seconds to find a shack, barracade all doors and find a weapon. Then hide in a wardbrode, hold your breath fully, let it recharge and hold your breath one more time, before you come out and continue with the game. This will make it far less likely Jason will detect you when he first uses his sense ability.
2) Order in which to equip things (if you have them): Pocket knife (prevents death if you're grabbed and stuns Jason), then fireworks (gives chance of stunning Jason, so you can escape), then first aid spray, in case you get injured.
3) Don't try hiding in cabins, tents or out houses when Jason has rage active. Your hiding place will show up red to him.
4) Look at the map and try to work out what other people are doing. If three or four counselors are together and moving around rapidly, it's likely Jason is chasing them! This is your chance to move to another cabin / to a vehicle / wherever, as he's likely being distracted. If a vehicle is moving away on the map (with you left behind somewhere), Jason is likely chasing it. Another distraction for him.
5) Keep an eye on the boat. If it has one component in it, look for the other so you can try and repair it and escape. Jason tends to take less notice of the boat than the cars.
6) If all else is failing, most of the other counselors are dead or have left and there's a minute or two until the police arrive, or until the game ends, find an outdoors hiding spot in the middle of nowhere and crouch down with your flashlight switched on. If you get lucky, Jason won't find you in time and you'll survive.
7) Keep an eye on the scoreboard to see how quickly Jason is killing. If he's quick, you'll need to be at your sharpest to defeat him, as he likely knows what he's doing. Try to second guess him. If he's taking ages to kill people, he might be an inexperienced player or just not that good. You can probably afford to take slightly more risks. Hide around the back of shacks or behind the bathroom door to try and escape him. This might fool the inexperienced Jason.
If you suspect Jason is cheating, quit the lobby afterwards. Signs he's cheating include: Ignoring a group of easier to catch counselors who are closer to him and going for you, lots of graphic glitches and screen lagging when he's near you, killing people very quickly with hardly any chasing, other counselors who appear to deliberately be giving your position away to him (trying to hit you, setting off fireworks for no reason near you, flashing their lights on and off near you and following you), starting the game and your counselor is not the one you originally selected.
Above all, if you're unhappy with something and things don't seem right, quit the lobby. If you spawn as Jason and you don't want to be him, quit the game. It's quicker and better for everyone!
A few tips, learned from experience! Hope they help