Firstly make sure you have some high level gear going into survival. I swapped my gear for anything health related, focus being next priority.
Choose Apollo as your god, the health regain will help a lot! Even better if your partner can choose this to. It's focus ability is slowing down enemies so I found this to be a bit of a blessing also, just be warned some can be outside the range and can rush you at full speed. Try not to go to far away from your partner as you could be asked to heal at any given notice, but at the same time try not to get two groups on you both at a very close proximity as they will easily rush you.
Lastly make sure you learn the attacks of all the enemies and when you should strike, knock and more importantly block!
These survival achievements are pretty simple as long as you watch your surroundings and the enemies attacking.