Like a business, you need 2 things to grow a following on Twitter
1. Attention
2. Quality Product

I've talked about how to get Attention before.
On a Principles scale: find your community, figure out where you fit, add value.
On a Tactical scale: quote tweets under 2k, create consistent content.
I did a podcast with @KyleTrouble & talked about it here http://bit.ly/2jUGwzn 

Let's talk about the first part of creating a Quality Product: Cohensive Theme
1. You need a very clear picture of who you are, what value you bring, and what you talk about.
2. You need to express that in less than 3 seconds on your landing page (account page)

You have 5 chances at this:
1. Name
2. Profile Photo
3. Cover Photo
4. Bio
5. Pinned Tweet
Every single one of these should combine to form a cohesive image of what you are about to someone visiting your page in under 3 seconds.

Here's my page now.
1. Name - Medici. Immediately think of Money. I work in finance. I talk about business, money.
2. Profile Pic - Statue of David - Renaissance Period (Medici again), known for having perfect proportions. I talk about how to get a great body.

3. Cover Pic - Statue of Atlas. Power image of strength, connecting to the Physical Development I discuss. Also appeals tho Randian idealists. Men as creators of their world.

4. Bio - Couldn't be more clear. Ties in physical aspects of my profile picture, cover photo and intellectual (money) aspects of my name and cover photo, as well as the Renaissance theme of my name.
5. Pinned Tweet - At this point it's hard to miss what you're getting from me.