Where do I get product templates?
http://arsenal.gomedia.us/product-category/mockup-templates/
Tons of mockups, both colored and ghosted
http://www.designbyhumans.com/designguide
Free pack from DesignByHumans
https://printaura.com/shirt-mockups/
Freebies from PrintAura, your LiveArt may also integrate with their system as well (wink).
Some freebies from DeviantArt
http://jovdaripper.deviantart.com/art/Vector-T-shirt-Template-143230813
http://madnessism.deviantart.com/art/T-Shirt-Vector-Template-39773099
Other templates offered on other resources:
https://yellowimages.com/all/clothing/
https://creativemarket.com/AntonioPadilla/199428-Infinity-Color-T-Shirt-Mockups
https://creativemarket.com/tyunderscore/235024-T-Shirt-Mockup-Template
https://creativemarket.com/cottonbureau/109341-100-Cotton-T-Shirt-Mockups-2.0
https://creativemarket.com/TheVectorLab/56675-Womens-T-Shirt-Mockup-Templates
http://clothingtemplates.com/