| Here's an easy way to convert a straight skirt to an A-line. You need a pattern that has front and back darts. Lay out the front pattern piece and draw a line down the center of the dart all the way to the hem-line. Starting at the waist, cut along the line to but not through the dart point. Do the same from the bottom of the pattern. You've now got a pattern slashed along the center of the dart with a hinge at the dart point.
Now here is the fun part! Close the dart by the desired amount, say an 1". The bottom portion of the pattern will swing open to compensate and voila, you now have an A-line skirt. Place a large piece of tissue paper underneath to fill in the gap and tape in place.
Do the same for the back pattern piece. Lay the front piece over the back piece to make sure that the flare is equal on both pieces. Next, make a muslin or pin the tissue together to make sure you like the amount of flare the skirt has.