Blast through your scale runs and create subtle texture differences in sound by mixing picking and legato. While there's little more satisfying than a perfectly executed alternate picking run, I'm a huge fan of injecting legato into the mix. Why? I believe there are two reasons:
Play faster sooner
I realised as a beginner (and struggling with alternate picking) that I could drastically increase my scale run speed by picking some notes and using hammerons & pulloffs to hit others. It gave my picking hand just enough of a rest during the legato sections to keep up.
It sounds great
I also realised that the mixture of percussive, picked notes and fluid smooth notes created a subtle yet pleasing sound difference throughout scale runs. See what I mean by giving this quick scale section a go, ascending and descending in C Major:
As abstract as this comparison is, I would compare the mixing of legato and picking to how a sparrow flies. If you've ever seen one flying overhead you may have noticed that they flap for a second or two and then tuck in their wings and fall for a moment, and then flap again, and fall again.
This is how picking + legato feels for me.
It makes me feel like a sparrow =|
Here's a brutal Jeff Loomis style shred lick using the technique!