DA42 pilot reported rejected takeoff due to no airspeed indication which was caused by the pilot not removing the pitot tube cover during preflight.

Narrative

Pilot was new to / transitioning to Diamond DA42 (twin). (15 hours in type)Pilot has significant time and experience in Diamond DA40 (single).DA40 and DA42 have similar exterior pre-flight walkaround procedures. On DA40 walkaround; pilot in command (PIC) was used to removing stall warning system cover and then immediately removing pitot tube cover; counting 'two' covers and stowing them inside the aircraft.DA42 as a different style stall warning system which does not get covered.On the event flight - the pilot conducted a pre-flight walkaround of the DA42 aircraft - including the typical items - securing baggage doors; checking condition of the gear/tires/brakes; checking the condition of engines and propellers; checking engine oil levels; checking flight control movement; inspecting the general condition of the aircraft; etc.However; because of the slightly different 'flow' between the DA40 (which the PIC was used to) and the DA42 - the pitot tube cover was not removed during the pre-flight walkaround.Normal startup; taxi out and pre-flight 'run-up' checks we completed. The aircraft was cleared for takeoff. After setting power and releasing the brakes; PIC immediately realized that there was no airspeed indication. The takeoff was aborted at low speed. The Control Tower was advised of the abort and the pilot requested taxi clearance back to the FBO ramp. A post-flight inspection revealed the pitot cover still installed. The cover was removed and a subsequent flight was completed uneventfully.Contributing to this event was the perceived similarity between the two aircraft models (both from the same manufacturer and of similar lineage). The pilot applied a pre-flight walkaround 'flow' from the previous aircraft type (DA40) to the new aircraft type (DA42) and slight differences in the aircraft configuration caused the pilot to miss removing the pitot cover.To correct this and prevent future mistakes - best practice would be to use the walkaround checklist as a 'do list' in real-time; item-by-item; for several flights until a 'flow' can reliably be established.