I use learned skills on every dive. I practice skills periodically on dives that I plan just for practice, leaving other dives just to dive.
I also evaluate all dives on completion to determine any areas that could use improvement. It might be something skill or equipment related.
Some things to ask are;
Was I in total control of my buoyancy through the entire dive? Check your computer profile to see if it agrees with you.
Was I aware of my location on the dive in relation to the exit location at all times?
Did I execute the dive exactly the way I planed it? If not WHY?
Did all my equipment work perfectly? This could be something like my regulator tugs when I look left or there are little bubbles from the fitting on the BC inflation hose connection.
While they may not put you at risk it makes you more aware of what is happening during your dives, and allows you to make decisions based on your diving.
I think a post dive evaluation is as important as the plan to evaluate my dives. It allows me to focus on what I need to practice or adjust to make my diving more enjoyable.
All said as a solo diver only you are able to evaluate, what you need to work on and when to practice skills. Plan it, execute it and, enjoy it.