Choose the Fabric
Step1
Choose a fabric - and don't be shy. Think vintage 1950s barkcloth with atomic icons, a modern remake evoking Route 66, flamingos - even an old chenille bedspread (preferably one with poodles!).
Step2
Buy 5 yards of fabric. For simplicity, try to get fabric that is 45 inches wide. This will give you a tree skirt just under 90 inches in diameter after hemming - big enough for just about any tree. If you want a contrasting trim, buy 15 yards (it sounds like a lot, but trims vary significantly in price).
Cut the Fabric into Four Quarter Circles
Step1
Fold the fabric in half lengthwise, and then in half again to make four layers. (You'll have a perfect square four layers thick - each side 45 inches.) Cut along the folds to create four equal squares; leave them stacked.
Step2
Hold a tape measure with your left hand at the bottom left corner of the stack, pull it out with your right hand to measure 45 inches to the bottom right corner, and make an arc by moving your right hand gradually to the top left corner of the fabric (stop and mark every few inches with a fabric pencil); this will define a quarter circle. (If you're left-handed, reverse these directions.)
Step3
Cut along the curve you've just marked to create the outside edge of your tree skirt.
Step4
Measure 3 1/2 inches in from the bottom left corner and repeat the arcing and marking step to create a much smaller quarter circle.
Step5
Cut along the smaller arc to create the cutout for the tree trunk.
Sew and Narrow-hem the Skirt
Step1
Take two quarter-circle pieces and place them together with right sides in, matching the small and large arcs.
Step2
Pin along one straight edge and sew, using a sewing machine.
Step3
Open out - you'll have a half circle.
Step4
Pin one straight edge of each remaining quarter circle to either side of the half circle, right sides together, and sew, using a sewing machine.
Step5
Open out - you'll have a full circle with a circular opening in the middle and a slit all the way through it - like a cape.
Step6
Narrow-hem the inner hole, the two long edges that form the opening of the skirt, and the outer edge. To do this, turn over 1/4 inch of fabric along the area you are hemming and press, turn over another 1/4 inch and press again, then machine stitch.