So, I am safely buried in CAD work at my new company and now have the lovely task of reviewing other people's 3D models in Inventor. Ouch! It is painful to see how other people (who are probably self-taught) model in 3D.

It reminds me of some of my pet peeves for people who don't know how to draft in 2D.

1. Don't use TRIM and EXTEND...instead make sequential little lines that are connected.
2. Don't turn ORTHO on...instead make lines that are ALMOST straight, but not quite.
3. Don't draw 1:1 scale...instead just draw to the size you think it should be.
4. Explode your dimensions and don't make them associative...put in the values you want, doesn't matter that the actual size of the object is.
5. Don't use layers. Put everything on Layer 0. Organizing a drawing is too much work.

I thought 3D was safe from these sorts of errors, but I was wrong. Here are the mistakes I am seeing.

1. Don't constrain your sketch to the origin. Just start drawing any ol' place. You can always add reference planes to your model if you need them. Who cares if it clutters up the file?
2. When you create your features, don't be concerned about how they will be maintained or how they are related to other features....for example, when placing a hole, don't use existing dimensions to ensure that the hole always shifts properly in relation to the edges if you decide to change the hole size.
3. When constraining parts, make a small component like a screw the central part that everything is constrained against.
4. Constrain small parts to each other instead of to the main body part...for example, set all the screw heads flush to each other instead of using a pesky insert constraint.
5. Don't include hardware in your assembly models...be surprised later when interference issues come up between washers, bolts, and screws and parts.
6. Don't use the hole tool...instead extrude cuts using a circular sketch...who needs hole notes? You can remember what that hole is for months later.