FUSION360 and Tinkercad

When it comes to 3d printing, or in fact most design processes, you are going to need some kind of CAD package.

For simple projects, I always default to the very useful (and free) Tinkercad.
All you projects and designs are stored on the cloud, but that doesn't really prove to be an issue.
You can export you design for 3d printing or laser cutting.  It's a very fast prototyping environment.

I have to admit, I push it's limits.  It doesn't have certain features that would be very handy, like chamfer, shell etc, but you can work around that.
There is a small library of parts you can pick from, including electronic components you can import.

On the left here is a small timer I designed for the Mission Impossible Fallout weapon.
If you need to throw together a quick bracket or enclosure, pretty much nothing beats it with regards to speed.

You can also import STL files from sources like Thingyverse.  Beware however there is a limit to the complexity of the part you can import.
On the right here is the entire Fallout weapon.  This is pushing the limits of Tinkercad and you will suffer quite a bit of lag working with this.

The largest workspace you can have is 1000mm square. 
But, as you can see, you can get pretty complicated with it if you know how to utilise the basic shapes available to you.

Exporting parts is easy, but I have found at peak times this process can be very slow.

Autodesk Fusion360

Fusion360 on the other hand can provide you with a far more capable CAD solution.
There is a learning curve, and I did a free tutorial on Youtube and that worked well.
It took about 10 days of evenings to get fairly decent at drawing what I needed.

On the left here is a rendering for an automated screen I designed for a London stage show.
Because the rendering ability is so good, you can make your designs and presentations to customers far better.

Tinkercad doesn't have a rendering ability.

It is a learning curve, and I find myself having to constantly go back and re-learn things, but you soon remember how to achieve the desired result.

I prefer Fusion360 as it has a Parametric modeller.  This means it adjusts the rest of your design if you change a parameter earlier on in your design (to a degree).

I have used Rhino CAD before and hated it, but many people love it.
I could not get on with it, as I found it far too complicated for designing fairly basic items.

I also didn't like that if you wanted to change something you had drawn earlier, it was very difficult to do that successfully (well at least for me!).

Below is a Fusion360 drawing of my rust bucket Ford Ranger.
To the right of that is a rendering of the same CAD image.

Apart from it was never that clean in real life, you can see the benefits of a decent rendering package.