I noticed myself falling behind on the lateral head. I ignored this for a while, remembering Arnold's advice to get massive before worrying about symmetry. I'm still not massive, but I couldn't help myself. I found this:

http://www.bodybuilding.com/fun/6-strategies-to-target-triceps-lateral-h...

The article talks about more than just the lateral head. My new routine:

4 Weighted bar dips (upright shifts load to triceps; don't lean forward, which is a chest dip)
4 Skull crushers
3 Cable pushdowns (overhand; keep elbows in)
3 Overhead DB extension (both arms)

6-12 rep range, but stay closer to 12, on arms/abs day in a 5-day split
Last set of every exercise is a drop set
Subtitutions: close-grip bench for skull crushers, one-arm overhead cable extension for overhead DB extension.

My old routine put triceps at the end of chest day. By this time I would be so tired that I would skip the dips; thus the lagging lateral head. Also I could not go as heavy.

That was just a long ditto to tonytulo, "Volume volume volume"

Also ditto to robb. It's about being lean. I could see a horseshoe when I weighed 147, probably more clearly visible than today, but much smaller.

The development of all muscles is down to your genetics. However some people don't realise what they got till the bf levels drop. In some it's just hidden away.

Rope and pressdowns. Volume volume volume. Time under tension , full range of motion squeezing at the positive (aka the bottom of the movement).....and the right nutrition.

After Chest I do either 3 sets of narrow-er grip bench or board presses for 6-8 reps Or 3 sets of weighted dips.

Then superset 3-4 sets either [cable push downs or dumbell lying french press] with [single arm rope cable cross body extension, or set up 2 bands and do a sort of kick back movement]. Been doing this for about 10 weeks now and the difference in shape is very noticeable, and arms are up .5 inch.

http://www.bodybuilding.com/exercises/finder/lookup/filter/muscle/id/6/m...