If you don't value yourself, don't expect others to.
The only thing you can control is your attitude.
Prepare yourself to be single all your life. Build friends, hobbies, self confidence etc so that you will always be content. If someone comes along, you can share with with them but don't rely on a partner to bring you happiness.
A third/half of every pay rise should go to savings for the big stuff rather than flittered away on upgrades or wants.
In work, if it's not in writing,it might as well not have happened.
If you are always honest, you can me er be caught in a lie.
Never bitch about someone's ex with them, far too often they re-appear.
Sometimes you cannot stop the car crash or rescue someone but have to let it happen and hope there are survivors.
Own your embarrassment. Brazen in out & it will be over sooner.
Your health is everything, mind it.
Take breaks when you need them,or your body will take them for you.
Never take the bait.