4lo in sand will probably only get you more stuck.
Vehicle speed is your friend in sand. Use 4hi as this will lower your chances of spinning the tires.
Try this
Before you get on the sand lower the air pressure in all your tires.
Use 4hi.
Remember vehicle speed (not wheel speed, wheel speed = digging).
If you feel your forward momentum stop, take your foot off the gas. At this point the only thing you are doing is digging yourself deeper.
Try reverse. If the Jeep does not go backward take your foot off the gas.
Digging out in sand is a lot easier than regular dirt. You can use your hands.
Assuming you took your foot off the gas & the axle or frame are not sitting on the sand...dig a trench out in back of all 4 tires. Place carpet, boards, floor mats, etc. under at least the rear tires.
Keep steering wheels straight. In 4hi back up. Once you get going go at least 10 yards, get out of the area you got stuck in.
If that does not work get out your strap.
Take a couple 2 x 10 at least six feet long, old pieces of carpet, or whatever you can find around home, work, etc. This is for traction if you get stuck.
Under no circumstance use 4lo in the sand. Remember, vehicle speed is good, wheel speed is bad. You want to 'float on top of the sand'. Using 4lo will dig you in.
I have been riding sand since the late 1960's and have found the above worked best.