There's a total of 30 Echoes, so you only need to 3 Star 20 of them to pop the achievement. I would make this your primary goal for the ECHO related achievements as the rest will come with it.
The following are the 20 I was able to 3 Star (some of them can be quite difficult). Just remember you can always check what skillshots you've completed and what are available to try and maximize you're score, and check your time bonus at the end if it's not very significant try to go faster as well because that's a good bump in points. Multiple times I would forget about the leash too, so don't forget you have that and THUMPING coupled with many weapons/environments can = big points. After the list I'll include videos of each if you'd like to see how I was able to 3 star them.
In order from when you can actually play them...
The Desert
The Hideout
The Club
Rooftops
Waterways
The Marina
The Power Plant
Forbidden Zone
The Park
Collapsed Building
Monorail
The Mall
Downtown
The Storm
Dreadnought
Gang Territory
Guns of Stygia
Crash Site
Monorail Factory
Meanstreet
Video Guide/Proof of 3 Star below.
1/20 The Desert
2/20 The Hideout
3/20 The Club
4/20 Rooftops
5/20 Waterways
6/20 The Marina
7/20 The Power Plant
8/20 Forbidden Zone
9/20 The Park
10/20 Collapsed Building
12/20 The Mall
13/20 Downtown
14/20 The Storm
15/20 Dreadnought
16/20 Gang Territory
17/20 Guns of Stygia
18/20 Crash Site
19/20 Monorail Factory
20/20 Mean Street
I've got a few more to add, but looks like I havn't edited em down yet so wanted to save this. Will update soon.