I like to use a feeler gauge
https://www.amazon.com/Hotop-Blades-Feeler-Imperial-Measuring/dp/B06XHXJG31/ref=asc_df_B06XHXJG31/?tag=hyprod-20&linkCode=df0&hvadid=241967215627&hvpos=&hvnetw=g&hvrand=1326352661310127251&hvpone=&hvptwo=&hvqmt=&hvdev=m&hvdvcmdl=&hvlocint=&hvlocphy=9015721&hvtargid=pla-361662223857&psc=1