With the rise of 3D printing, there has been a great increase of software that will gladly help you out to create your own designs. Google created Sketchup, Autodesk even has its own toolchain that will allow you to design and print objects. Often, these applications have a set of limitations - be it legal (not for commercial use) or functional (some features are not available, e.g. limited export functionality).

Are you looking for software that is free to use, without restrictions... then you're bound to end up finding FreeCAD. This great application is free and open source, yet currently very actively developed and user friendly. Furthermore, next from running it on Windows or Mac OS, the software unleashes it full potential when running under Linux.

Looking for help? Maybe in your design process, or maybe you're looking for a new feature? The forum has a vibrant community and the development environment is tailored to do magic if you know some basic Python programming... you can easily create your custom extensions...

I'm not an engineer or hardware developer myself, but can really enjoy the strenghts of this great application.

With displays increasingly getting higher and higher in resolution, having rasor sharp images is a must. While photos have to participate in the megapixel race, there's a lot of artwork out there that gets a much better effect if it gets stored vectorially.

I love Inkscape because it allows me to use multiple layers and easily create and place objects together. Fairly simple objects (like f.e. safety icons) are small in size, no matter what the dimensions of an image are.

A nice feature I love to use, is the option to import from PDF and then extract certain details.