If you are too disgusted with your democrat option to vote for them (I assume no one is following me who would vote for republicans?) Anyway I think it's helpful to still vote and write-in something or check out the local referendums and just vote on those.
Your null vote weakens republican and democratic mandates. Just telling people you feel that was is less impactful.
It also increases overall turnout numbers which mostly freaks out all of the right people.
I think voting for democrats is the most effective option in nearly all cases, but I don't like cheerleading for them much.
The constant vote vote vote from people who never show up or help with anything else can be annoying.
People will tell you a null vote is wasted. I don't think so. It's alarming.
IDK maybe don't do it in a swing state, but that's up to you.
Just show you can and will show up.