Several websites sell templates. Each an every template is different. It's good for learning but how to manipulate these templates to create a completely new track? Or how to add new elements to it?

 

Well, these modern so-called templates are just a completed track or construction kit. Instead of selling the stems they sell the project. I'd say they are targeted toward wannabe's and amateurs to make some quick money.

Templates generally should be made by You, creator of the project, to help speed up your daily process by doing common tasks and save it as starting point. This way you can focus more on being creative.

Like if you're a mixer, you could load a trim plugin before fader to make everything just below -18 dB, Which is equal to 0 dB VU and is called plugins sweet spot. Or if you're into dance music you may sort tracks by categories using a related name and a specific color.
For example, setting all the drums to purple and making a pre-made kick with a 4-on-floor pattern so every time you want to start a project, you just have to load a sample and set the project BPM.

 

Thanks.

 

I used to like to go through templates and see how they did their fx chains and returns.

 

here is a template i made. when going to arrange drums, i extract each hit into its own channel. any ideas on how to improve it?

 

Making your own templates would be the wisest imo. Workflow, usability, convenience, flow, etc.

You remove/add as you wish. The problem could be that once you get your own creativity going you might figure out that this template isn't right for you, so you end up changing/swapping out quite alot of what is in the template.