I'm learning tremolo picking. I learned it in one string, but when I try to do tremolo picking in other strings I can't, particularly in the high E string. Is it a good idea to buy single strings to build a custom set so that every string has a similar sensation? Perhaps this will accelerate the learning curve of tremolo picking.

Also, what do you think of Alice picks?

Gadgets, gizmos, hacks, tricks, they’re all distractions from the only thing that will get you better at what you want to achieve: practice. Wanna get there faster? Work harder. And if despite putting the time and effort, you feel your technique is holding you back, consider investing in quality lessons from a professional.

Alice picks work just fine. Brand and material are bullshit, the only thing that really matters in a pick is the gauge, and maybe the edge/bevel (but not that much). Choose something that complements your weaknesses. I, for example, have a fairly light touch, so I never go below 1.2 if I can help it. If instead I was rather heavy-handed, then I might opt for something lighter like a .5 to avoid getting it stuck from the excess force. Think about the way you play, and try to get something that matches your needs.

Good idea!

I learned it with a certain part of Metallica's 'One' Solo. You must learn to take the swinging of the string with every next pick.
Eventually it will feel natural and it doesn't matter anymore on which string you play.
Also make sure that you cover most of your pick and only use the tip of it. Do not use floppy and bigass picks.

I suggest Dunlop Jazz III if you are searching for the extreme

Best advice!

It's SO true about 'gizmos, gadgets, hacks, tricks etc'....they're all BS!
A great guitar player can wail on a 100 harmony guitar with a tiny watt Fender bullet.
Also cross train playing classical guitar music.

This very comment echos what I would say too......if you find yourself on a plateau, get some lessons.....plus youtube is a great resource.
There was no damn youtube when i started playing so I think it's so cool for young players to get better relatively quickly.