The following simple guidelines have worked well for me :

1. Don't use ng-repeat. Instead use Collection Repeat which is way faster and well optimized for Ionic apps.

2. Use less number of one way bindings. Less bindings mean lesser number of watchers which improves the performance. Also avoid $scope.$apply() and go for $scope.$digest(). This is because $apply() triggers a digest cycle on the root scope whereas $digest() starts the cycle on the scope it's called on.

3. Don't add custom watchers unless you really need them! Keep this number low. Dirty checking always results in poor performance.

4. As suggested in regular web apps, always minify, concatenate and mangle your CSS/JS files.

5. Don't use too many filters.

These are the things I follow while building Ionic apps and I have got good results. May be Adam Bradley (@adamdbradley) can shed some light on this.

You might also want to use Crosswalk. Crosswalk provides Android developers a bundled Chrome webview for their projects, resulting in better performance and predictability!