Canvases are designated by holes per inch – the higher the gauge the finer the work. Choose canvas gauge carefully. A six thread stitch on 12 gauge means half an inch: fine for pictures but easily snagged on cushion covers.
Beginners usually start cross stitch on aida and progress to linen or other evenweave fabrics as they get more experienced – but not necessarily.
When dealing with irregular shapes, make an accurate template of the area to be stitched before you start.
Always use rectangular canvases/fabrics, whatever the shape of the project.
Polished canvas costs more but is worth it because it will not ‘fuzz’ threads when pulled through.
Allow approximately 2 inches extra per side when cutting your fabric/canvas. Where appropriate, rinse all excess dye from fabrics and remove folds.
Although there are conversion charts for different manufacturers, take care when replacing colours for complicated pictures. You need to preserve the relationships between tones.