Remove the existing fabric from the sofa, if necessary, using a staple remover. Inspect the bottom, legs and arms of the sofa for repairs. Tighten loose springs or replace damaged padding with a sheet of synthetic padding. Skip this step if covering a new sofa.
Take the vertical and horizontal and width measurements of the back, top, inner back and sides of the sofa. Note any decorative curves or contours along the front of the sofa. Also measure the sofa cushions. Provide 2 inches for seam allowance to the measurements.
Spread the new sofa fabric on a clean, hard surface. Trace the measurements on the fabric with a colored marker. Also trace the sofa's arm and cushion measurements on the fabric. Cut along the outlines using sharp fabric scissors, so the edges are thread-free and straight.
Center and place the new fabric on the sofa's frame. Enlist a helper to hold the sofa while you begin stapling the fabric to its bottom back. Stretch the fabric up over the back, inserting staples to secure it to the padding and frame.
Pull the fabric taut to one side of the sofa, attaching it with staples. Bunch up and fold extra fabric underneath, if necessary. Stretch the fabric to the other side of the sofa and repeat the process of attaching it in place until the sofa is completely covered.
Sew sections of fabric over the front and top arm panels by hand, if necessary, using transparent thread and an upholstery needle. Measure the length and width of the sofa section and allow 1 inch for seam before cutting the fabric to size. Sew the fabric directly to the padding.
Sew slip covers for the cushions using a sewing machine, with a zipper attached to one side. Sew decorative trim or tassels on the cushions for added effect, if desired.
Inspect the sofa fabric for frayed or loose edges. Snip loose threads or tuck frayed edges underneath and staple.