I make them out of inexpensive wood scraps, so they end up looking rustic. Basically, they would be a prototype for someone with actual Woodworking skills. They all include a substitution cipher message and code wheel. They are usually single movement puzzles. The "Sweet as an Onion" cryptex required multiple positions to solve, and the recipient was never able to solve it, so I lean into the simple designs unless my friend is an expert puzzle solver. I usually go for hidden pocket puzzles, but my current favorite design is a variant of the snake cube puzzle that assembles into a functional code wheel to solve the message woodburned into the blocks such that if assembled in a second configuration reveal an encrypted message and instead of letters, I used Cistercian numerals. Each puzzle also tries to embrace the onion philosophy, where each layer is easy to peel, and leads to making the puzzle easier to solve. Clues are usually hidden on the object to eventually guide solvers to solving it instead of trying to frustrate or defeat them.