This is the HTML version of a hand-out pamphlet that we use in the Canton of Wolfsgate. It shows you how to make a simple piece of medieval-ish clothing. The construction method is not strictly period, but the end result looks good enough for your first few events.
Alternatively, you can use broadcloth or whatever you find in the remnants bin. Strong, primary colours are best, with browns and tans less usual. The concept of "matching" was unheard of in the early Middle Ages, and it was common to wear red with green and yellow.

Second, fold the cloth in quarters, raw edges together first and selvedges together second. Note the corner that corresponds with the centre of the fabric.

Third, take a loose fitting sweatshirt or tee-shirt and fold it in half, lengthwise. Lay it on the folded fabric with the lengthwise folds together and the neck at the corner that corresponds with the centre of the cloth.

Mark the outline of the t-tunic using your shirt as a guide. Leave an inch or more for seam allowance and to allow a bit of looseness in the fit. Extend the sleeve line out to the edge of the fabric. Choose either a close fitting sleeve (solid line) or a wide, hanging sleeve (dashed line, usually for women). Extend the sides into a skirt and mark the bottom in an arc.
Fourth, take your shirt off the cloth and cut where you've marked.
Fifth, make the neck hole. Be careful! Most people don't know how tiny their neck really is... measure the thing, first.
Open the cloth out by one fold and make a "D" shape centered on the fold and as big as your neck. Your neck sort-of grows out of the front of your chest, not straight up between your shoulders. The neck hole must reflect this or your garb will ride against the front of your neck and be uncomfortable.
Flip the cloth over and mark a MUCH shallower "D" on the back. Cut this out.
To get it over your head, you need a hole bigger than your neck. Cut a slit down the front of the tunic from the neck hole just far enough so that you can get your head through. Cut this by degrees until it's just right. Since this makes the neck look a bit like a keyhole, it's called a keyhole neck.

Sixth, sew up the sides and down the sleeves (dotted lines).

Finally, turn the thing right side out and it's ready to wear. Cinch the waist in with a belt and wear tight fitting pants and you're all dressed to come to your first event!
thescholarsgarret.com),
known in the SCA as Master Henry MacQueen of Longhouse.