There's a film I love called The Five Obstructions by Gus Van Sant. Basically, there's an older director (Leth) who is depressed and contemplating suicide. Van Sant, his mentee, tries to think of a way to deter him. He comes up with a challenge: Make 5 different versions of Leth's 1967 film The Perfect Human, and each version comes with one distinct constraint, or brief, that he has to follow.

The older director accepts the challenge, and has a fine enough time until one of the constraints is that... there are no constraints. Anything goes. He finds this incredibly difficult.

Most of us assume constraints are limitations, when in reality, they're essential to creativity. Having no limits and all directions available is totally overwhelming, as Leth learned.

Impose constraints on your project, whether that's your next series of paintings, or identifying your next career move.

Quick ways to constrain yourself 

1. Give yourself a timeline and deadline (less than 6 months away).

2. Limit yourself to exploring 3-5 ideas; you can avoid analysis paralysis and excess time "shopping" around for the right concept.

3. Make sure it's a SMART goal (Specific, measurable, achievable, realistic, time-bound)

You can start there and then come up with more constraints as it applies to your project (location-bound might make sense, for example). Then, you can rub your ideas up against these constraints and see what comes up. Your undertaking will feel more concrete and defined.