Create an escalation procedure
even if you are a sole entity. You know how long a project should take and you probably know at what time you will reach a certain stage. If you are getting behind schedule, escalate to the owner, the vendor, a colleague, someone. The longer you take, the more frustrated you become and the less you can think straight. Get help.
Keep a log as you work including every action taken, whether it was right or wrong. If the action was not the right one, learned from it. What did the action do, how did you recover from it, etc.
It isn't just a case of knowing what to do, it's also a case of knowing what not to do - and WHY not to do it.
Use a digital recorder from the oment you get onsite or start a project. If you work to a script or procedure, you only need record deviations from the procedure.
I did this for twenty years in corporate BCP/DRP and continue to do so a consultant. It makes life so much easier when billing the client and creates a record for your database.