Well, As stated earlier, My goal is to design board such a that any DIY PCB etcher can do.

So, I gave special preference to net classes, by making all of them to 1 mm. [thicker traces are best in Iron based toner-transfer method]

I choose DipTrace PCB tool to design the board, It's really an easy tool to work with.

Speaking of placement, I followed K.I.S.S.[Keep it Smart & Simple] rule, and tried well for it.

Placement:

Routing: