Start in a neutral pose and put the clothing on your figure. Go to a later frame (the number doesn't matter, but I use 10 for this example), and pose your character. When you set up your cloth simulation, set it to start at the default pose, and set perhaps 5 frames for draping. When you reach the 10th frame, the clothing should drape and be compatible with the pose. Then render the 10th frame for the final pic.