Maybe you want to take some looks around. K.C.s Advice is already great.

- You may use Resistors and Diodes as vias since they have feet which are solderable on both sides

- You may want to keep the traces straight or in 45° Angle for a much cleaner look

- You may want to not use 90° angles, for etching it is better to have 45° angles.

- You may want to use as less vias as possible (Source of Error and work ;-)

- You may want to add a indication which Layer is Top and Bottom.

If you are etching your own PCB, you might want to change these as you don't have plated through vias:

Make sure that *all* of your traces to terminal blocks, headers and other parts that have pins under their footprints are on bottom side.  i.e. do not try to use their footprints to jump layers.  Make "vias" outside their footprints.  Otherwise, it is a pain to be soldering between these parts and the surface of the PCB.  Seen too many of these rookie's mistakes.

Mounting them flush would make them mechanically better - When you push connectors down, the part makes contact with the PCB, not the solder joint.  When you pull a connector, the solder joint is under compression, not trying to peel off the pad/traces.  Also a pain for "shields" if you have to lift up the pins partially for solder joints and end up with uneven heights. 

Solder your two drivers before the diodes as the diode blocks your access to the pads on the surface.  Solder the connectors last as they are tall parts blocking access.

Mounting holes for the PCB?

thank you for your advices !!