Choose a small result
A folded booklet, a page of drawings or a set of photographs is a clearer goal than learning an entire craft. Write down what you would like to have in your hands at the end of the afternoon.
Use a materials limit
Look through the materials you already own. Choose a project that fits them, and make a short list of anything truly missing. A smaller selection reduces the time spent deciding and leaves more time for trying.
Reserve the last few minutes
Set aside time to put tools away and note what you learned. If the project is unfinished, leave a specific next step rather than a vague intention to return someday.