Starting a clothing brand

TheBiz

I'm looking into starting a clothing brand, it's something I've toyed with for a long time..
Brands like 11 degrees, Sik Silk, Hera London.. basically targeted towards teen lads.
As well as High Fashion brands like Fear of God.

Where can I can I create mock up designs online?
I can find god know's how many templates for plain t's but nothing for curved hem, muscle fit, oversized, side splits etc..

I want to look into cut and sew, manufacturing, trying different fabrics etc.. I have an idea in my head I'm just looking for online resources.
Can anyone point me in the right direction.

wmpdd3

In this brand, what will be your responsibility?
Designing and manufacture or just designing?
I'm not familiar with the brand's you mention and I didn't study men's wear, but some friends from college have started a brand with success.
As it was fashion design that we studied, most of my friends only designed and outsourced manufacture.
Do you know how to use illustrator? Can you make clothes, or do you know how they are constructed? Do you have any experience with pattern drafting?
None of these things are essential, but will decide what your role could be.

I use cut and sew for knitwear, would you mostly be working with interlock jersey / french Terry?
Look up early YouTube videos of how Gymshark started out.

Dramatik

I'm not sure if I 100% get what you're looking for are you looking to mock up the actual clothing items online or just looking for templates to see what printed designs would look like on different items?

If you're just looking to see what your images would look like on different clothing items you could maybe try a site like: https://www.bagsoflove.ie/ which offers printing on many different types of items bags,jackets,caps etc