Draw it the way you want on your graph paper....then measure and line off "graph paper" on the board you intend to use to make the front curve of the valance and draw the pattern, reproducing what is in each small sqyare of the graph to the larger one.
No formal training here either...but for experience.
Linda C

If I understand the situation correctly, I've handled this sort of thing by scanning the not-to-scale drawing and manipulating the image with Photoshop to make it a scale drawing, then print it out full-size (in sections) and glue the printouts to the template material with spray adhesive.

To lindac: I did that in art class when I was in high school, a long time ago, and it works wonderfully if I am duplicating a drawing that is to scale. For example: The shape covers a width of 24 squares on the graph paper, and I am told the actual width is 48 inches. Then one square is equal to two inches. And the height matches that scale.
My problem comes in when someone else is making the drawing without considering the scale at all. I get a drawing in which the shape covers 33 squares and the actual width is 45 inches, and the height is actually 10 inches but drawn to cover 8 squares. The width of one square is 1.36 inches, and the height is 1.25 inches (that is not really a square). How do I make a template with those measurements?
Thanks for the try though.

If the original drawing is in proportion width vs height, there's no problem, you can draw a grid over it to represent inches (use dividers) and scale up from there. In the future, ask for full-size details.
Hint- you can transfer full-size drawings to the material with a pattern wheel- it looks like a small corrugated pizza cutter.
Another way to transfer a line is to apply pencil graphite to the back of the drawing @ the line area, then trace very carefully onto the workpiece- it's like home-made carbon paper. This also works with the pattern wheel.
Casey

To jon1270: I get the thought. Like using a light projector to show the shape on a wall then moving the projector forward or back until the shape matches the acutal dimensions.
Well I do not have photoshop, a projector, or an image to project. Thanks for the try though.

can you just redraw it using the DIMENSIONS? On a new piece of graph paper, using 43 squares for 43 inches, etc.?

And *then* enlarge it?

If the drawing is not to scale, then it's probably not proportionately representative, and it won't look the same, and it's not your fault.

So, draw it, small, on graph paper, using the true written dimensions, then compare it to the original, and show both to the client to get sign-off.

Once the client signs off on how the mini looks, then transfer it bigger to inch-square graph paper.

Here is some old-time-carpenter's geometry.

If the curve is an arc (part of a circle), it is easy to draw using three nails and two boards.

Both methods require you to put a nail at the end point and center of the arc. Then get two boards and create either a half-lap or gusset to hold them together at the ends. It does not have to be fancy or neat.

Method 1:
* Put the two boards joined so they create a "triangle" or large "V" with each board (same edge) touching both one end point and the center point.
* Fasten the boards to maintain this angle (let glue dry, nail together, etc. whatever works for you.)
* Put a pencil in the apex of the V and keeping the boards in contact with the left and center nail, trace the left side of the arc.
* Repeat for the right side.
Note if the V apex angle is 90 degrees, you will have a semi-circle (half circle).

Method 2:
* Lay the first board from the left nail to the center nail as before.
* Attach the second board PARALLEL to the chord (the line connecting the endpoints of the arc.) The easiest way to do this is simply measure from the chord up to the midpoint and mark the same distance above the right endpoint.
* Securely fasten the V as before.
* Remove the center nail.
* Trace the arc with the pencil in the apex, keeping the boards in contact with each endpoint nail.
This method requires longer boards, but is one operation and not two.