Starting with a simple lego shape, I created these illustrations using Adobe Illustrator and some Isometric guides. 

Here we can see how I drew by hand the different Orthographic projections of the first picture lego shape.

Three flat Orthographic views, top, left side and front. 

Finally the Isometric views of the object.  For this I used an isometric grid, that was adapted from a premade file. then it was  just a matter to first rotate the flat views from the previews file, to create a flat shape of the views and then the Isometric shapes using the grid and snapping to intersect points. This was very fun!