There are many ambigram tattoo generators freely available online. The easiest way to access these resources is to Google "free ambigram generator." After locating several designs, consult a professional for advice on which works best as a tattoo.
Be cautious when designing an ambigram tattoo. Make sure to consult a licensed professional who can provide education about what designs make a good tattoo. Ambigrams can be especially difficult to read unless they are well-designed. A well-designed ambigram is easily readable from both directions and most often contains words of the same length.
Remember that what makes a good tattoo is often very different than what makes a good drawing. Clear, bold designs in outline form that are easily readable from a distance are preferable since ink can fade and blur over the life of the tattoo.
Always be safe when choosing an artist; first, make sure that he is licensed. Also, make sure that the shop is visibly clean, and the artist is operating in a professional manner. A good artist always opens new needles and pours ink in a client's presence. Make certain to research various shops in the area to compare work, as different artists specialize in different types of work.