I always bury my knots. I usually do a twice wrap of the thread to make my knot, sometimes three wraps if I think the knot will pop back through. I pull the knot down to the fabric and using a pin/needle, separate the threads of the fabric enough for the knot to pop through and then using the pin, coax the fabric weave back together. I also leave a tail after the knit buried in the sandwich whenever possible.