Space is a dangerous place being full of radiation and flying rocks. If you are out there long enough you are liable to get hit by one of those rocks, and if it doesn't kill you outright it would do some real damage to your air supply, i.e. it would all be leaking out through the hole the rock made.
Dividing your ship into air tight compartments that could sealed off, much the various chambers in a modern naval submarine can be sealed off, would be a good first step. But what if you are caught in the chamber that has the hole? Putting on a conventional space suit is slow and cumbersome and you would die before you even got it out of the locker where it was stored.
I'm thinking a set of coveralls, with booties, made out of a space age polymer might be just the ticket. You would need a helmet, but a hood that came all the way over your head and fastened at the neck line in front might work out just fine. There are a couple of problems with this. The first is that you would get wet wearing a plastic suit, so you would need some kind of ventilation. The second is that once you got it on and the chamber you are in lost all its air, you would swell up like a balloon. Being swollen isn't so bad, but it could make moving your arms and legs a bit difficult.