I am thinking it might be an idea to work within a calender month. So, the parameters are set at whatever time, for work to commence the start of the following month. Your item to be posted, if possible, at or around the end of that month.
That means, we set the ball rolling now, for work to commence on the 01st of May, then be posted out around the end of the month, or earlier. Around the 20th - 25th of May parameters are set for June etc etc
Maybe change the size or shape of the piece each month or couple months. Do the 3" X 5" for a couple of goes, then change to 4" diameter circle, then 1" X 5" strap, vary thickness, maybe put up a design subject on some occasions - flowers, western theme, water theme, Sheridan etc etc.
Any other ideas to keep things interesting?