Aside from recognizing capital losses, several common ways to lower AGI are to make deductible traditional IRA contributions, contribute more to work retirement accounts like a 401(k), or contribute to an HSA. Of course, you have to meet the eligibility requirements for these options.
If none of those work, you should pay attention to the bottom of Form 8962 around Line 28 or so to see if you benefit from the repayment limitations associated with having an actual income higher than your ACA estimated income. If your AGI is below certain breakpoints, then the amount of ACA subsidy you have to repay will be limited.
Other than that, I'm sure it is a learning experience to measure twice and cut once.