An open weave fabric is much easier to work in to than a tightly woven fabric. If using knitted fabric, make sure it is not a tight knit.
You may find it best to work a sample piece first.
Before starting it is important to work a tension square. The height of the rows does not matter but the width of the stitches is VERY important. Count how many stitches you have per 2½ cm (1 inch).
Mark the fabric into sections 2½ cm (1 inch) sections, about 5mm (¼ inch) from the edge.
Using a darning needle, poke holes carefully in to the fabric, using the mark as your last hole per section. The number of holes per section should equal your stitch count.
Fold the fabric over so the raw edge is in line with the row of holes and carefully work a dc (US sc) in each hole. Make sure all raw edges of the fabric are covered.
If working corners, make sure you work 3-4 stitches into the corner hole.
Once you have all your raw edges covered, you can carry on crocheting as if it was a regular crochet item.