To design an ambigram, write the desired word forward, then again in reverse order under the original. Observe the letters that fall into the same vertical column, then select or create a font in which the paired letters can be combined into single figures.
An ambigram is a way of writing a letter, text or phrase so that it can be read the same upside down or right side up. This means that each letter should appear as another letter when it is flipped upside down. For example, adding an extra horizontal line to a capital "V" means that it will be read as an "A" when flipped upside down. The key is to make these combined shapes clear enough that an individual letter can still be parsed.
While an ambigram can be made with any font, some font choices may work better with certain words. For example, if the word is quite short, or is a palindrome, simple block letters can work well. If the word is longer and more complex, script-like or Gothic style fonts are generally easier to work with because they have serifs and accents that can be easily turned into components of other letters. In the case of longer words or words with an uneven amount of letters, the text may have to be written so that two letters appear as one other letter when flipped.