Have you created enough items to fill an online store? Whatever you are planning to sell chances are you are going to need to boost production before you go live with your store. How much stock are you going to need?
The best advice is to list as much inventory as you can before officially launching your store whether your store is on Etsy, another online craft market or your very own site. Create as many items as you are able, and be prepared with supplies on hand to make more when something sells. Generally the consensus amongst long term Etsy store owners is that 40 items or more is a good number for starting an Etsy store.
If you only have the ability to offer a few things at one time, create as much as you can to list and then create additional listings with options that can be custom made, if appropriate. You can also create bundle listings giving customers the option of buying more than one of your items for a saving and that will add to your number of listings, making your store feel fuller. Don't stop production after you have listed your items. Keep producing and regularly list something new in your online store.
Boosting production is also going to mean that you need to purchase items for your creations in greater numbers. Buying all your materials in small quantities from retain craft stores isn't usually a sustainable business plan. Source your materials online from sites like Etsy, Craigslist and Ebay and buy in larger quantities. Think creatively about the materials you can use to create your items. Repurposing fabrics and notions is a great way to add charm to an item and keep costs and expenses down.
It can be tough to stay motivated to produce your handmade items in large numbers. Setting a routine will help and individualising each piece is a nice way to exercise your creativity so you can keep loving what you do.