It is tough to make an attractive garment if you start with fabric that is off grain. One great way to get many woven fabrics on grain is to tear the yardage all the way across the full width of the fabric. Start by making a small cut thru the selvedge edge, and then let ‘er rip! (Meaning – tear from the cut across the full width.)
Most cutting layouts asume the fabric is folded in half with the selvedge edges aligned. Now you should be able to fold your fabric in half, “lining up” the selvedge edges and the torn edge of your prepared fabric so that the entire piece is smooth and flat. If there are no ripples or twists near the fold of your fabric – yay for you! You are ready to start cutting out your pattern.
If there is a “twist” near the folded edge – you need to “skootch” the top half of the fabric up or down a little until the twist smooths out. Got it? If the selvedge edges are aligned, and there are no twists or ripples now, ready, set, get those pattern pieces on your fabric. If your fabric is still bunchy and twisted, you can try pulling it back into shape. Get a pal and each of you take a “diagonally” opposite corner and gently pull on the yardage. Try folding the fabric again, lining up the selvedge edges, and see if the ripples and twists have been eliminated by the stretching. If there are STILL ripples and twists – pitch it. Some fabric cannot be saved. Do not waste your time and energy on lousy fabric.