Read a Tinkertoy Building Manual
Because Tinkertoys have been around for so long, past Tinkertoy architects have devised several tried and true designs. To create a classic Tinkertoy structure, pick up a copy of manual or book such as Dylan Dawson's "Tinkertoy Building Manual." Simple graphic instructions will show you how many pieces you need and will give you a step-by-step guide to an array of impressive structures. Even if you want to create your own ideas, a pre-established design will give you an outline from which to start. Look for designs that have similar structures to your own ideas. Follow some of the steps until you have a base. Then add your own flourishes to the base to create a new structure.
Create Models of Famous Buildings
Browse through a book of the world's most famous and iconic monuments and buildings. Photocopy a page from the book and draw over the picture to brainstorm ideas for how to use Tinkertoys to depict the building you want. Note the angles and dimensions of the building, and translate those into Tinkertoy format. To assist your design, lay the Tinkertoys over the picture. This will give you a sense of how different parts of the building or monument will translate into Tinkertoy format.
Vehicles, Toys and Animals
Not every Tinkertoy structure has to represent a building. Tinkertoys are flexible items that work well for a variety of different designs. Think of your favorite animals, and use your Tinkertoys to create them. Or perhaps you like cars, planes and trains. Take a look at your existing vehicular toys for inspiration on how to make Tinkertoy versions of them. Or perhaps there's a toy you really want, but you can't convince your mom or dad to buy it for you. As you wait to acquire the actual toy, use your Tinkertoys to make a model of the toy you want. Who knows, perhaps your Tinkertoy version of the toy will provide more hours of fun anyway.