Extrude print to adhesion plate printing

#1
How do I set up prints to extrude some filament prior to atarting the real print. I have an issue where the first 10-30 seconds of printing does nothing. Essentially I want to prime the hotend for a better start to the print.
 
#2
This is what I do.

G1 X300 Y15 Z0.3 ; move the platform to purge extrusion
G92 E0 ; zero the extruded length
G1 F200 X395 E30 ; extrude 30mm of feed stock
G92 E0 ; zero the extruded length again
G1 X150 Y150 Z25 F12000 ; recenter and begin

Add that to your startup script right after the temp is set.
Make adjustments as desired of course.