I promised this many moons ago, a basic how to, so to speak. Basically if you can knit socks you can make liners for your clogs/crocs. What you are doing is making something similar to a trainer sock.
I used 50g dk. 3.5mm & 4mm DPNs.
First measure around the opening of the shoe, this will tell you roughly how many sts to cast on. Remember you will be stretching the rib, so you have to take that into account.
Using 3.5mm Cast on X (68 in my case). Rib for desired length. (This is the fold over part).
Divide for Heel
Put half sts on needle one (34), divide remaining between needles 2 & 3 (17). Change to 4mm needles, work 8 rows stocking stitch, on needles 2 & 3. With right side facing continue as follows;
Slip 1, K half the heel sts, slip 1, psso, K1 turn
Slip 1, P 3 sts, P 2 tog, P1 turn
Knit rows; Knit to 1st before the gap (where you turned) Slip 1, K1, psso, K1 turn
Purl rows; Purl to 1st before the gap, Slip 1, P 1 psso, P1 turn.
Repeat last 2 rows until no sts left to turn. (18)
Pick up sts along the gusset turn, purl to end, pick up sts along other side gusset turn.(5sts both sides in my case)
On a normal sock you would now work needle 1 ~ we are NOT going to do that. But we will take a stitch from it on each row.
Working on needles 2 & 3.
Place marker. K2, K2 tog through back of loop, K to last 4 sts, K2 tog K2. Place marker. K1 from needle 1 turn.
Purl to end, P1 from needle 1.
Continue until you have decreased down by the amount of sts you picked up from the gusset. ( I now have 52sts on 2 & 3). now we work Needle 1. I Knit across it decreasing 6 sts evenly so I had 46 sts in all. If you knit socks you will know roughly how many you should have at this stage. I think I should have left this at 50sts.
Continue in stocking stitch until about 2 inches short of desired length.
Put ½ sts on Needle 1, this is the sole. Find the center stitch from the heel and use this as you guide. Divide the remainder between needles 2 & 3.
Decrease toe as you would normally. In my case it was as follows
Needle 1 ~ K1, K2tog Through back of loop, knit to last 3 sts, K2tog, K1
Needle 2 ~ K1, K2tog Through back of loop, knit to end
Needle 3 ~ K to last 3 sts, K2 tog K1
Next row and every alternate row K.
Repeat until you have about 18 sts left. Graft together. I'm lazy so I just knit the corresponding sts for both needles at the same time and cast off.
I put the clog heel strap over the arch and used 2 strands of yarn to tie the sock in place.