And here are a few more I got, at the same time. For best results, you may want to "roll" the sheet down onto the shaving cream. That way, you can see if all of the sheet is going to make contact and fix it before you get big white blobs! (I learned the hard way...see the last one.)
Number 2: Swirled some more first...

Number 3: More swirling...and only a quarter page. I did drop in a bit more magenta, which shows up at the right.

Number 4: Scooped in some of the white shaving cream from the other end of the pan...

Number 5: Still more white. The "faux deckle" from the torn edge is beautiful!

And the "bad" one...it had white areas from trapped air. I tried doing it again, but it didn't go so well. Oh well.

It's hard to tell from the scans, but numbers 4 and 5 are actually much lighter. I swirled in more of the white shaving cream, and it resulted in a much more subtle finished product.
It's actually a good strategy to try and get some bold ones and some subtle ones from each "print run." It works especially well if you do larger pieces for the first couple and then switch to smaller ones. After two or three, you'll find that the level of the shaving cream is getting low. If you switch to smaller sheets, you can mound up the remaining shaving cream and get a few more prints. The last two were easily light enough to write on...