A proper lens hood shouldn't add vignetting. However, if you put the lens in a longer tube you should start to get the effect. You might also get the effect if you use a long lens hood while at a wide-angle setting. Here is one I took deliberately using too wide an angle for having my Raynox adaptor mounted on the end of my lens:
That might be more dramatic than you want. Possibly a different kind of mask over the end of the lens would work better.
On the other hand, perhaps it is best to apply the vignette effect in post processing - that gives much more control over how it comes out.
Wulf