Insect repellents. You may wish to use fda approved insect repellents as well as sensible clothing choices that have long sleeves, tuck your pant legs into boots as well to offer more protection for the legs. Also try to avoid heavily wooded areas if possible.
Avoid grass. Chiggers live in long grass and bushy shady areas so try to avoid these areas. Wearing long sleeves and pants with thick socks and high boots or shoes with pant legs tucked into the boots can help prevent infestation. Apply deet to skin and clothings to repel the chiggers. Chiggers don't like hot (above 99 f) or cold (below 60 f).