Once you have checked your kit, the weather conditions and the avalanche risk, you should be able to set a pretty good route. It is important that you also have some additional plans in case something goes wrong. There is no ‘official’ amount of contingency plans required, but generally speaking you need two or three extra routes, just in case.
These routes should then be discussed with the entire group in case of separation, and importantly left with somebody you trust and who you can contact once back safely. Finally, never be afraid or ashamed to turn back. The mountains will still be there for you to try again under more favourable conditions. Pushing on regardless not only endangers yourself but also risks the safety of the people who may have to come out to help you.