Get a digital voice recorder and note the idea WHEN you have it.
Write all the ideas in you idea book, mix and match
Let the current moment in time dictate waht project NEEDS to be done today.

handling multiple projects.

The hardest part by far is getting off my ass. The sooner the better . It will only keep getting harder to do the longer you wait.
Most prodjects require certain weather conditions so catgorize projects by what weather permits what.

Ideally a team will do better than an individual so if you have not done as well as you thought you could oas an individual, make a team.

Once you have some success you can hire a team and make art factory style. If you think that is wrong, you are wrong.