3d Prints.
So... At this time we think that everything is already invented...
And I keep making new stuff...
New Idea, mini vacuum cleaner... only found one design online and was so badly done... So I made mine.
Happens all the time... Search, nothing I like, do it myself. And worst, I'm not even good at CAD programs lol.

Any Ideas for tools to make?

It happens to all of us. First, you need to research about you want, how it works and what are the critical parameters. Second, grab a 3D design program that you like. Here I can do some recommendations:

For a complex mechanical piece, you should use a CAD like Fusion360, SolidWorks or FreeCAD. They take some time to learn but it's worth.
For a simple mechanical piece you can use OpenSCAD, which might be faster if you know math and programming. The disvantage it's that you need to render the final piece to export it as STL and this can take hours if the piece is too complex.
For artistic or organic pieces better use a software like Blender, 3D Studio, Maya or SketchUp. Again, depends of the complexity, your skill in the program and the time you want to spend.

@LuxARTS I Basically use Fusion 360 for everything :D I have knowledge of solidworks and it's very similar.

I don't like Fusion360 because it saves the files in the cloud so you need internet access to open it from another computer. Also it's very slow in my notebook. FreeCAD it's a bit more complex but runs smoothly, and it's free and open source!

"Everything is already invented."

Um. What?

Someone doesn't have an imagination. And doesn't read. Or think.