they say it takes 17 "yes's". As you're going through your pitch or whatever you do, I'm sure you have opportunities to work in little things like, "that sure sounds good, doesn't it?" (et.) to an obvious scenario where the answer would be, "yes." There's a TON more "tips & tricks", but mostly you need to learn to recognize buying signals that customers are always giving out.
Hopefully you are making friends with these people? People buy from people they like. For some people it's just natural. I worked with a guy once (a LONG time ago) who just had it. He got started in sales because his dad owned a tire store. Most of the cars that came needed new shocks (like I said this was a long time ago). None of these "salespeople" could seem to sell shocks. They could sell tires but not shocks (easy to see you need tires - not so easy to see you need shocks).
This guy turns 16 and wants a job, so dad hires him to sell tires and shocks, with the emphasis being on shocks. Teaches the kid enough about shocks and why they are important and off he goes. This kid goes on to sell more shocks in a month than they've sold in over a year. They also had a couple car stero stores. The guy works in the family business (moving to the stereo side) and is always the top salesperson. You meet the guy and instantly you feel like he's your best friend and you've known and trusted him for years. He could relate to all types too. Men, women (especially good looking women!), businessmen, drug dealers, you name it. He can sell anything. Doesn't matter what it is, he could sell it and anyone would buy from him.