This is actually a complicated subject that many books have been written on.
To vastly oversimplify there are two ways to look at Talismans. The first is based on cosmology.... most use astrology as a cosmology so I'll use that as an example. When you are born you are a miniature copy of the universe as it was at that moment. You may find that you don't have enough money or love or something. Perhaps this was because Jupiter, which can have to do with money, or Venus which can have to do with love, were badly aspected when you were born, or are badly aspected today to the way they were when you were born. This can be overcome by making a Talisman that adjusts your relationship to Jupiter or Venus.
The other way to look at it is psychological. You have some sort of internal psychological complex or neurosis that prevents you from making enough money or getting enough love. You make a talisman as a symbol to help you reprogram your subconsciousness (which speaks a language of symbolism) towards achieving what you want.
These are perhaps only one way of looking at it with psychology being a more modern cosmology than astrology.
In any event, the making of talismans is about the manipulation of either internal or external forces in order to get what you want. There are as many ways to make and use talismans as their are magicians.