My tip - if you recently bought an item, it's easier to pull the pic from e.g. the ASOS website. Otherwise use two different duvet covers/ blankets/ or use your existing flooring (one pale colour and one dark) and lay out really flat under good lighting. Then you can take pics of your own clothes and get a good contrast. It is laborious to start, but saves me loads of time - I can plan outfits whilst queuing/at the bus stop. Maybe just focus on the clothes you'll be wearing in the next few months only.