NEVER trust a hydraulic jack with your LIFE!. A $0.25 O-ring is all that is keeping a jack 'up'. Always use a 'life saver' block of some kind just in case the stands lean over and the car falls. The wheels+tires (mounted on the hubs) are OK if you can slip underneath without any jacking (I can't--too 'thick) I use the wheels ( or spare) with 2x6 across it to increase height enough and provide assurance any stand failure will land on the wheel+timber block.

I use 4 ton rated stands made by AC Delco, not cheap no-name/house brand junk.

NEVER yank on a wrench hard enough to rock/sway the load on the jackstands or jack. Use an impact wrench. Brace yourself against the car (use your feet against something) if you are pulling hard to avoid stressing the stands with sideways loading--they are rated for Vertical loads, not side loads.