Doorframe and Door Tutorial
Tools and Equipment needed:

Wall
1/16" (1.5mm) wood
1/8" (3mm) square strip wood
Moulding for door frame
Craft knife
Mitre cutter
Tacky glue
As I didn't think of making this tutorial until after I'd made all the doors and doorframes for Weybourne, I'm using as an example here the door to a built-in cupboard beside a chimney breast, which is why there is so little wall on either side of the doorway.


To line the doorway, measure the thickness of the wall, and cut strips of 1/16th (1.5mm) wood that width.  Cut one to fit across the top of the doorway, and two more to fit from below the top strip to floor level.  Glue into place.
I can't tell you what size to cut the pieces of wood, as you will have to take your own measurements as you go along.  I usually start off with a doorway 6.5" x 3" (165mm x 76mm).

I hope my conversions from inches to mm are correct.
To prevent the door from swinging both ways, you need to put in a stop.  Cut pieces of 1/8" (3mm) square strip wood, one to go across the top of the doorway, and one to go down each side.  Decide before gluing which way you want the door to open.
Now trim round the door with the moulding, mitering the top piece at each end, and the side pieces at the top, cutting straight at floor level. 
You need to do this on both sides of the wall.
Measure the opening in the doorway, and cut a piece of 1/16th (1.5mm) wood to fit.  Remember if you want the door to open over a carpet to leave a gap at the bottom for this.
To panel the door, using the 1/16th (1.5mm) wood, cut two strips of wood 3/8" (10mm) wide x the length of the door, and glue down either side of the door, ensuring that the outer edges of these strips are flush with the outer edges of the door.

NOTE:
1.   If you want to stain the door, cut all pieces and stain before gluing, as wood stain will not take over glue.
2.    The widths I give for the strips are the ones I usually use.  You might prefer to make yours different.
Cut a piece of wood the width between these side pieces x 3/5" (15mm), and glue in position at the bottom of the door.
Cut two pieces of wood the width between these side pieces x 3/8" (10mm), and glue one in position along the top edge of the door of the door.
Glue the second one across the door so that the panel it forms is square.
Cut another piece 3/8" (10mm) to fit between the centre strip and the bottom strip, and glue into position, making sure its centred on the width of the door.
Cut another six pieces as above and glue to the other side of the door.  The door in now ready to be painted and have a handle fitted.

If you want the door to be hinged, you can use bought hinges or little strips of leather.  In Weybourne I haven't bothered with hinges,but have just stood the doors in the position I want them to be.  Because the doors were made to fit the doorways, they stand in place very easily.