If you have a home buisness, how can you attract new clientele to buy from you?

I sell mostly on Etsy and also participate during the season doing local art shows. Etsy has been a great platform for me. You might want to check it out.

If you're a home-based business, it's especially important to fine your "people" or create a community that your products will appeal to. Join local business groups, in your case find opportunities, like art show's and markets and of course be active on social. Good luck!

Networking, listing on wedding sites, personal contact with wedding venues.

Art is a personal item, you just have to work on being seen more. Get into local galleries, keep your website up today and post on local media. 

I participate in two art websites.   Fine Art Studio On Line FASO, which i pay a monthly fee to exhibit my art.  I am also on Saatchi Art.  It does not charge but takes 35% of the selling price, so you have to inflate it if you want what you think is the full value.  Go to FASO.com and Saatchiart.com for more information.   I also have done several commissions mainly by referral.  I also belong to Jefferson Art Guild.  JAG, but they just want paintings, oil, watercolor, acrylic, mixed media on relatively flat canvases.
Hope this helps.
You might also try Pinterest.

I read all the comments below and I saw some pretty good advice - some that I think might use myself so thanks for the question. I still haven’t cracked the code on marketing. I would emphasize that an online presence is important but you can’t reach everybody this way so you need to decide your target audience. For your line of work that seems pretty obvious to me. Focus on getting your work seen through those types of venues that will reach your target market, both locally and national. FB has thousands of fan pages and closed groups for different categories I’m sure they have plenty for Bikers. You can use that venue to get your work out there on a broad spectrum. I sold a fair amount of my prints this way. You just have to work with the admins of the sight (don’t break any rules)  Videos seem to be the best way to advertise online since everyone seems too lazy to read. So some footage of you doing your thing with a little dialog would probably go a long way. Maybe post on YouTube as a “how to” as well as FB and instagram and your own website. Because you sell Biker helmets with artwork, I assume you offer custom painting as well as your own designs, if you don’t I think you should. As far as your own designs make them something that will appeal to your audience and pull their heartstrings a little. My first thoughts are subjects like patriotism, gun rights, veteran themes, freedom, vicarious lifestyle, rebellious attitudes things like that. If your work sends a message they like AND is fun to look at, I think it will sell better. Last thing, think long term- you have the right idea on expanding your merchandise and service, don’t limit yourself to just biker helmets branch out when you can with tanks, jackets, hats, shirts, saddlebags. The more You have to offer the more reason to shop at your store. Just be careful not to invest too much in merchandise until you have the customer base to support it. -Good luck

   If you love what your doing then you can sell it. Problem is you think to much. I don't know anything about art at all but I guarantee I can sell more then you by going door to door with paintings under both arms lol. On a serious note. You need a salesman. Its that simple. If your not willing to get out there and do everything it takes to make the sale then find someone that can sell and give them a decent percentage

You could expand your business on the internet.  I know there are many out there. I have used SFI for 6 or so years and once set up does bring new business.    https://www.sfi4.com/11972575/ec