Hot to market my models?

Agree with just about everything 3DCargo said. I'll just add that if you're going to use Social Media as a way to market yourself, and I recommend doing that, be sure you're developing a following that is relevant to this artform. For example, if you have a Facebook account or a Twitter account but most of your followers are just family and friends outside of the CG industry, posting your work there is useless. Make sure you build a social media presence that contains contacts and peers in the industry. Artists, filmmakers, animators, game developers, CG enthusiasts. These are all people who might be interested in purchasing 3d assets. Instagram and Facebook have special interest groups dedicated to different areas of CG. Twitter is fine, but I find it's less effective than some of the others at finding your niche.

I dont have a direct answer for you but I can provide you some food for thought:

- Provide Value: look at it from the customer's point of view, what is the value you are getting? Does it speed up my workflow, is it difficult to make so buying this item will save me time, does it make my renders look better, does my client need this item to market their product accurately, can I re purpose some of the assets for other products/projects etc.

- Content: When you are on twitter are you interested in models that are selling on the marketplace, if so - why, if not - why not? If someone models something you like emulate those reasons/emotions in your own content. Would you be impressed with a coffee table and some quick text below "buy me now its on discount!" - probably not, you probably don't like being sold to like that so why would you expect others to? I'm not saying you are doing this just an example.

- Marketing: Its a skill that takes time to develop or something you can hire others to do (that's why we give a commission to cgtrader). I heard this concept once and I think its a useful frame of mind - you need to sell the idea not the product. So the example they provided is when you want to fly to a destination you aren't informed about the engine or wingspan of the aeroplane, the technical things that don't interest you. You are sold on the idea of the beautiful location, the food and culture you will encounter, other peoples experiences/reviews etc.

- Niche: Define who you want to sell to. Who will benefit most from your products and then tailor your content to them. If I scroll through twitter and I see a bunch of cartoon characters I think 'oh nice' and keep scrolling. I wouldn't even read the description since I'm not looking for cartoon characters. I work with archviz clients, so if I see a really well made plant that my customers keep asking me for ill stop immediately and read more. Sometimes the more niche you go the better, so instead of "I build plants for archviz" you would triple down on that and say "I build Australian plants for offline rendering, high quality close up photo realistic / photo scanned geometry". When you corner a market you become the professional in that sector, people will want your expertise in that area and/or refer you to others. You can always branch out later or experiment but consistency is key and when you nail a niche you should see fruit from your efforts. If not, don't be afraid to ditch the idea after a certain milestone and try something else.