The three options are chalk (or wax) in the form of solid lumps or pens and pencils, tailor’s tacks or snipping the fabric. Snips are used in industry and they can be quick and easy, but if you’re still relatively new to sewing my advice is to avoid them – if you make the snips too big, you will weaken the seam allowance and in lightweight fabrics the snip can keep going and cause a tear in wovens or a ladder in knits. Tailor’s tacks are accurate, but they can fall out as you handle your fabric. My favourite method is tailor’s chalk in a lump or pencil, or a marking pen (although I do mark precise pattern markings like buttonholes with lines of tacking in a contrast colour). Use a selection – you’ll find they each work better on different fabrics. I’ve also heard plain old soap works well!
Some people don’t like using the lumps of tailor’s chalk or wax as they get blunt quickly. I find them good for some jobs and you can sharpen them – either buy a special chalk sharpener (yes they do exist – just search online for “tailors chalk sharpener”) or run scissors along either side of the edge (obviously not your fabric scissors!). Chalk is better for firmer, woven fabrics, wax can be better for knits. Recommended brands: Hancock’s, Prymm. Beyond Measure have a great selection of Hancock’s chalk and wax, in lumps as well as pencils and crayons.
For those who don’t like the lumps of chalk and wax you can get various forms of chalk and wax pencils. Some are just like ordinary pencils that you sharpen, but I often find these a bit too hard and can really drag some fabrics. I prefer these style of mechanical chalk pencils that you can buy refill leads for. Wax also comes in a wax crayon form which is really easy to use. You can also get marking pens that look like felt tips that are either water or air dissolvable (beware the air dissolvable ones as the markings disappear quickly!). Recommended brands: Hoechstmass, Sewline.
Chaco liners are used a lot by quilters and are great for precision marking and for use on delicate fabrics that are easily dragged by chalk or wax, eg. silks and lightweight jerseys. The marks do rub off easily though as the marker uses chalk dust. Recommended brands: Clover, Prymm.