I like to respond to requests immediately upon receiving them (whenever possible). This shows the prospect that I value their business and am responsive. I do not send “form” emails, yet I do have a template that I use and input relevant information and pricing. I found that another very important tool is getting positive reviews. When prospects see my profile with over 20 reviews it garners more trust. It also helps with getting more leads (or so I’m told).
It’s also important to realize that there are some leads that are just not serious about paying a designer what we’re worth. I found that if I get a 15-20% conversion rate I’m doing ok.