I'll try to help the best I can with any tips or guiding towards achieving any specific medal. Since I have got all the medals myself, I can say that I feel confident helping anyone out how to do it.
First off all there are 3 steps of requirements.Step 1:
Skill! Are you noob or just don't play that much. Then stop wasting your time...Step 2:
The Medal-system is kind of ¯\_(ツ)_/¯ (If it hasn't been a recent patch for it yet). The 5 weekly medals will be randomly obtainable and you need to cross your buttocks that you'll see the ones your after to appear. Be patient.Step 3:
Some medals are really hard to get, don't get mad at the game or your counter-players for ruining everything for you. Beacuse they will!
Any other than that. Fire away!