This is a tough one to easily duplicate as the ellipsoidal is made specifically for this purpose. The ellipsoidal zoom is a focusing unit with lenses at the front and the ability to also move the light source at the rear to vary the projection size and sharpness hence the zoom designation...so it provides the opportunity to very precisely place the projected image. As I said, mine is adapted to strobe use so I can vary the power as necessary.
THe old school way of doing this kind of thing was to cut out a shape in a foam core board and place a hard light behind it, moving the board and light source to achieve the result. Lots of variables in that equation...size of the board, distance to wall, distance to light source etc. It can be done but it's time consuming.
The other advantage to the ellipsoidal is that stainless steel cookies are pre-made. I have quite a few... a variety of windows/leaves/etc.
FWIW< I do see them on craigslist from time for very short money. I don't think many people really know what they are (they're traditionally used in the theater for lighting effects, I don't think there's many used in still photography these days). In fact, mine sat unused for a few years and I was close to letting it go for very short money. The next thing I knew, I had a job that screamed for this effect. Glad I hung onto it!