i recently got offered one of these - though my species was Leptothphlops goudotii
very interesting and unusual species. requirements - i dont think much is known. i dont know where your originates but Leptotyphlops occurs in south and central america. due to its burrowing nature it could be deduced that temperatures should be a little lower than the usual temperatures for species of that area. if i do accept this specimen i would probably keep the ambient temperatures at around 28 - with a cool end of around 22 and the hot end perhaps 30 degrees celcius tops.
bearing in mind these are burrowing they will not require a light or any other light emitting heat source, in fact i would say this could be harmful to them as they could be very sensitive to light. as a heat spot i would use a heat mat underneath the vivarium to heat up the substrate, as they are burrowing snakes.
in the wild my species occurs frequently in termite mounds or soil - i accidently dug one up in belize whilst digging a hole for a tree. i would provide the snake with some loose form of soil, perhaps the coconut fibre stuff. i would also use leaf litter (certain leaves only, i believe oak is a good one) as they are frequently found in that. they are active at night and day, so with leaf litter acting as cover that might result in you seeing slightly more of the animal.
for my species i would have relatively high humidity, as they come from areas with a high humidity, so for me around 80% seems about right, i would also add a very shallow water dish with lots of small islands and sloping exits as im sure they could drown quite easily.
i cant see them needing a particularly large enclosure, both species dont really grow about 50cm - mine not usually getting above 12 inches - so a 2 or 3 foot vivarium would be ample for a pair or a small group, which leads me to the next point.
these snakes are insectivores, therefore i think it would be fine to keep a group of this species. my species is sometimes found in small groups that arent believed to be mating groups - though it is unknown what they are. the only issue is feeding. i would try small 1st and second instar crickets - i think thats the best chance of them feeding. my species feeds on termites, small ants etc.
i will be happy to help if you want - i have got to be quite good with working out husbandry requirements - i have to be in order to keep half my stuff thriving. i may have waffled on speaking about an irrelevent species, but im sure some of what i said will be of use - i hope so!