I recommend continue using with out store for couple of months.
After couple of months you will get to whether to open a store or not depending on the sales flow. If you are able to achieve 2-3 sales per day with out a store , then i highly recommend to open a store. Because this will boost your sales more higher.
Offer attractive prices, On almost all items offer free shipping, Reply to buyers immediately after payment and tell them i received your order and will be shipping soon, Get good packing material (in your case use cardboard boxes as you are selling jewellery which have chance to get damaged in transit, Get subscribed to some courier service (I Personally got subscribed to First Flight Courier and they charge me monthly with 20% discount on all consignments)This is mandatory because it saves a lot on shipping charges.
But at the beginning i recommend not to open a store so early, get to know by trail and error on how to list,do some search on ebay.in and see other sellers how much they are selling for, Write some attractive description which can be easily read by a buyer.
This is all personal experience and i believe every seller recommends not to open a store too early.
Hope this helps, if i missed anything please let me know
thank you
