Hi mshideler, often times people just model different parts directly in place, that can be a simple way to do things.

Unlike the traditional solid modeling method of having a separate "Part" and "Assembly" programs or modes, in MoI you just work in one environment where you can have multiple objects if you want or just one object if you want.

There are some different tools to accommodate different ways of working though.

If you want to model something directly in place, you can use the View > CPlane tool to set the construction plane to some specific local area and that will cause the drawing plane and the Top/Front/Right views to be oriented around that local area so that you can more easily draw things in that spot directly:
http://moi3d.com/2.0/docs/moi_command_reference5.htm#cplane


If you like to model parts in separate files you can do that as well - there is an "ImportPart" command that can help with that:
http://moi3d.com/2.0/docs/moi_command_reference1.htm#importpart
That's available by right-clicking on the Import button and that will let you open up a model from a separate file and then allow you to place that model into the scene and rotate it into place using the orientation picker.

If you want to model several parts within the same environment and then position them into place, you can do that too - to do the positioning step you use a combination of some Transform commands along with object snaps for placing each reference point in the transform to precisely position things together. Construction lines can be helpful for this stage as well. The Transform > Orient command is probably the most general tool for positioning objects since it handles both moving and rotating an object into place within the same tool:
http://moi3d.com/2.0/docs/moi_command_reference8.htm#orient

See here for a discussion on how to use Orient:
http://moi3d.com/forum/index.php?webtag=MOI&msg=3424.13
http://moi3d.com/forum/index.php?webtag=MOI&msg=3424.14


And here are a few demo videos Orient or ImportPart in action:












There is also a PastePart command that is similar to ImportPart, but that lets you bring parts over (and position them) using the clipboard instead of a file import:
http://moi3d.com/2.0/docs/moi_command_reference4.htm#pastepart


So there isn't just one way to do such things - you can use whichever of these methods you prefer. There isn't really any one of these methods that I'd consider to be a better or a "best practice" as compared to any other, just use whichever method you feel most comfortable with.

- Michael