Spread a thin layer of glue (not too thick, but definitely not runny) onto a sheet of transparency film, or some other smooth surface, like glass (if you're up to washing it afterwards), and gently place your lace onto it, making sure it touches the glue everywhere.

What is the best glue for lace?

Ghost Bond XL With Extra Moisture Control

It is the best glue for lace front wigs because you don't need to worry about the glue for your wig melting away with this product. This powerful adhesive is no match for your natural oils or sweat.

What can I use instead of wig glue?

Bobby pins, wig clips, an elastic band or a wig grip would work best. However, you can also use tape or glue around your edges for a strong hold.