The answers to the clues below will have something in common.

1. Treat tivially
2. Get wise
3. Sawing logs
4. Clear up
5. Be discovered
6. Inconsequential
7. Parsec parts
8. Move unencumbered
9. Motivate
10. Easy to lift
11. Furnace feature
12. Dance
13. Inspiration
14. Relax
15. They don't speak, but we obey.

Answers:

1. Make light of
2. See the light
3. Out like a light
4. Shed light on
5. Come to light
6. Lightweight
7. Lightyear
8. Travel light
9. Light a fire under
10. Light as a feather
11. Pilot light

Credit: LA Times Crossword
Sylvia Bursztyn and Barry Tunick
LUMINOSITY (#1-8)
12. Trip the light fantastic
13. Guiding light
14. Lighten up
15. Traffic lights