I have one of these and it seems to help.

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https://www.amazon.com/Astromania-Bahtinov-Mask-Focusing-Telescopes/dp/B01MEGIA85/ref=sr_1_2?dchild=1&keywords=bahtinov+mask&qid=1607614494&sr=8-2

I affectionaly call them 'bhatman mask'. You put it on the lens/scope, focus until you see a very sharp three dotted diamond image, and that means you're in focus.