I would be able to advise you better if I saw your website or knew what your niche was but there are two broad principles you should follow:
1) Optimize what you are already doing
You are already getting leads. So, it's not a traffic problem as much as it is a conversion problem.
Keeping this in mind here are some of the things you can do to improve lead quality:
a) Improve the copy on your website. Your positioning and your USP should be such that the right people are attracted and more importantly, the wrong people are turned off. Focus on what your ideal clients look like, and then write the copy around their pain points.
b) Nurture your leads better
Do you have a lead nurturing system in place? If the lead asks for a price, do you ask them to submit a form where you attempt to get more context and insight into their business challenges? Do you run an autoresponder campaign where you highlight the issues your potential customers might face if they dawdle over the transaction?
Sometimes, people might have the budget but they might not have the talking points to sell you to their bosses. It's your job to give them that ammo.
2) Once you have optimized your current processes, you will need to find out new ways to get leads.
You can target a number of channels depending on how much your customer acquisition costs are and the projected customer life time value is.
I would be glad to work out a lead acquisition strategy for you and help you execute it if you can give me some more details.