You own 100 shares of GE. Sell the 100 shares of GE for a loss of $10. Next, buy 1 Sept 22 call 24.5 strike for $0.04. The call purchase will trigger the wash rule, so the cost basis for the call is $10.04. Next day buy back 100 shares of GE. Following day, sell the Sept 22 call for $0.02 giving you a loss of $10.02. You have just harvested your losses.
You can do the same without options if you have used FIFO accounting in the past. Using just stocks, do the following: You own 100 shares of GE. Buy another 100 shares of GE, this doubled your holding to 200 shares of GE. Next day, sell 100 shares of GE for a lost of $10. This lost is tax deductible if you used FIFO accounting. If you used LIFO in the past then only the options method will work.