Let's start at the beginning.
You need more quality listings. Where will they come from?
Let me ask a question.
Where are your current Seller clients coming from?
Your branding and your online presentation of current listings will bring new Seller clients to you.
Why? Because they saw your sign at a home.... maybe your online presentation (Realtor.com or Zillow or your website) and could be judging whether they would want you to represent them when they sell their home. They may want "what Mrs. Jones received when she listed her property with you". Or not.
Secondly, Sellers statistically go online from 6 weeks to 3 months before listing their home. They are checking how their home compares to what is on the market and for an estimate of what their home might be worth. They are doing their own research before contacting an agent.
They are also, even though subconsciously, evaluating the quality of each listing agent's photography and presentation online. They may choose the one that had the most listings in their neighborhood if they are selling... but most often, they will choose the one who provides the best marketing. Their goal is Sold!
So, unless they choose to use their close relative who is a Realtor... the online presentation of your listing could win them over. After all, if they have to pay $X commission .... why not choose the one who provides beautiful professional photography, global and local marketing, lead generation, weekly Sellers Report, floor plans, video, aerials and more.
My tip, You need to kick up your marketing plan from plain to premium to get more listings. Today's sellers have heard it all. If you offer what everyone else offers, you will compete on price and personality only.
Top Agents understand exceptional marketing demonstrates their reach and will sell their property faster and for more money.