Roughly 30 percent of our population puts in a scrawl that looks like a diseased staphylococcus aureus as their signature. And then they are surprised when bailiffs come with receipts they didn't write and loan agreements they didn't sign. The longer the signature, the harder it is to forge.Letters
You can build the signature around the last name or add the first letter of the first name. Sometimes capital letters of the name and surname are combined into one monogram, but Russian tsars used to do it that way, so it looks pretentious. It's better if the signature is just handy. So put at the beginning voluminous letters - O, E, R, V, M, N, L, if you find them in the surname or first name. And you should end well on letters with vertical lines - R, U, F, D, Z. It is easier to make curls and other decorations from them.
The task of curls and monograms is to create more intersecting lines. Then the signature is no longer open - one in which it is easy to trace the direction of the stroke. The more intersections, the more effort the forgery requires.
According to our laws the signature can be anything - even a text, even a drawing of a cat in a washing machine. The main thing is to be able to reproduce it by hand. And to answer the psychiatrist's questions, if you are asked.
Changing your signature does not demand any formalities and replacement of documents, unless you are the Chairman of Gazprom. In that case nobody will ask you to do anything. However, if the signature does not coincide with the passport signature, the bank might suspect it, so it is better to leave a sample of the new signature there.