I regularly played outdoors in hay fields and farmland in Cheshire as a kid. As young teenager, every other weekend and each school holiday I was out and about in the Welsh countryside, mostly along the upper reaches of the river Clwyd (fishing and generally enjoying the countryside and farmland) . For the last 25 years my job has involved regularly walking about outdoors on farmland, wasteland, etc. and to this day (touch wood!) I've never found a sheep tick feeding on me!
In recent years, given the Lyme's disease issue (and the associated risk assessment process) I've wondered why... and the most likely explanation I can think of is that, most of the time, I've worn tall wellington boots, with my trouser legs tucked into my socks inside them. Wearing wellies so often, and for hours on end, led me to buy comfortable, good quality, natural rubber boots, which tend to be tailored to fit the leg reasonably well and not have big gaps between the leg and shaft into which all sorts of invertebrates could fall when walking through long vegetation. I also suspect sheep/deer ticks might find it hard to impossible to crawl up the smooth shafts of natural rubber wellington boots, plus trouser legs tucked into socks would prevent access to skin if any did make it over the top!
If my thinking is right, I wouldn't rate my chances in a pair of textured cloth type neoprene wellies, I imagine the ticks could get a gip and cling onto those, plus I've never been a fan of that type of boot due to the semi-absorbent nature of the outer fabric and the need for me to disinfect my footwear between visiting different sites (biosecurity). So maybe a pair of tall, comfortable, well fitting, natural rubber wellington boots is the way to go; with shorts, ankle socks and hiking boots being the tick's best friend? Also, perhaps, don't sit down or lie down in long grass, bracken, etc. and keep your long trousers tucked into your socks.