Remove any existing fabric from the chaise. Rather than cutting it off, use a flathead screwdriver or a pair of needle nose pliers to remove the staples or tacks holding the fabric secure. This will not only give you a clean surface to work on when it comes time to attach the new fabric, but will also give you a template to work from when cutting the new pieces of fabric.
Measure the dimensions of the chair. Account for the size of the cushions and include them into your measurements. You could also measure the chaise's old fabric since it will provide an accurate measurement of just how much fabric was needed to upholster the piece originally.
Purchase the necessary amount of upholstery fabric. If you're uncertain about how to properly translate your measurements into fabric amounts, store employees will be able to help you with this.
Use a fabric marker to outline the shape you need for your chaise. If you're reupholstering an old chaise, this is where you'd use the previous fabric as a template to make the task easier. Working from scratch, you'll need to lay the fabric overtop of the section you're upholstering to get a general estimate of the amount you'll need. Draw an outline on the fabric, making sure to include a couple extra inches along the edges for folding and hemming.
Cut the fabric into usable sections with fabric sheers. Each piece of fabric should be able to completely cover the section of the chaise you intend to upholster.
Lay the fabric flat on the horizontal part of the chaise and fold it around to the underside. You may need to do some folding around the corners in order to ensure a tight, clean fit. Secure the fabric to the structure using heavy-duty staples from a staple gun.
Fit the fabric to the upper portion of the chaise. Depending on the style of the chaise, this means either covering the entire surface or only the front portion. For all-over coverage, fit and fold the fabric over the surface before securing it in place with upholstery tacks along the middle of both sides. Staples hold the fabric to the bottom of the chaise. For pieces with only partial coverage on the top section, hem the edges and then secure it in place with upholstery tacks.