Here's a relatively easy ambigram I did recently.
The solution to this word was for the most part pretty trivial. The symmetrically placed n's immediately stood out as promising ambigram material and most other combinations were easily solved as well. The t/o pair on the other hand appeared less cooperative, but its solution has a nice touch to it.
My t/o conversion is by no means original—for example, Robert Maitland already used it in his Bounty Hunter ambigram. But for this specific ambigram I added an additional meaning to it: the t/o glyph also resembles the alchemical symbol for antimony ().