One thing that I've been doing that has helped me come tax time is having a basket of ETFs bought with lump sums at different times. Whenever there's a 10% correction, I sell the etf with a loss and just replace with one that has historically similar performance but is not considered substantially similar to trigger a wash sale. I do this with VTI, spy, schb etc and a few others. There's usually at least one 10% correction within a year and I make the trade simultaneously from one to another.