Redo of CAD standards, best approach for setting up lineweights?

I am pretty much starting off from scratch, everything was such a mess!

End result desired:

- Metric and Imperial Library?

- Layer standards

- Plot standards

Should I specify lineweights within the blocks? - And then have plot lineweights set-up by object lineweights? The lineweights were previously specified by color, but it doesn't work. (Office wants all electrical to pop-out and all other-architectual-to be the same thin lineweight).

Any hints? Tips?

Well it depends on your plot styles. Are you going to be using CTB or STB Plot Styles?

Usually CTB plot styles are used in most plotting environments with AutoCAD. Most people on this forum board uses CTB. Assuming this, its highly recommended to set all entities within blocks to "ByBlock". Of course there will be acceptions to that rule, if you need certain things within the block to plot thinner or thicker then you would assign a color to it that will not change.