I know this is "under review" so to speak, but I would echo this. I went back Jeremie's swing thread; his receptivity to direction and subsequent swing changes has demonstrated his dedication, and his obedience has born out marked improvement. Nice job, Jeremie!
Lessons, depending on your arrangement with your home course, can be a much better way to make money than if you just work in the shop.
In the shop I would imagine you're not making much more than $15 an hour, even as a professional, assuming that you aren't salaried to run the golf operation for a city. Even if you charged a relatively cheap rate of $50 an hour for lessons, and the course took half of your inexpensive fee, you would be making $10 more an hour than you would otherwise and it might be more enjoyable that pro shop work for you. Playing lessons could be even more lucrative depending on your rates, and you can even play some golf yourself (either playing with the player or demonstrating a shot, for example).
Youth programs can be highly profitable if that's something you're interested in. A local course with two PGA professionals has a weekly group lesson for junior golfers at $20 per person. On the days that this program is running they easily have 30-40 kids ($600-800) out there working on chipping and putting (and then the kids go out to walk nine holes afterwords). Depending on how your course operates and how busy it is this is something you could look into organizing. Put up flyers both on the course and in public areas where you are allowed to post things to get the word out.
If you are somewhat tech and business inclined it might be a good idea to look into starting up a small business of your own selling golf apparel and equipment. Take advantage of your PGA membership and start up accounts with the major brands such as Titleist, PING, Taylormade, Scotty Cameron (they kind of do their stuff separate from Titleist) and put up a storefront on your own website. Squarespace is one web-hosting company I know of that does an excellent job of making it easy for you to put together what you want. Nearly everything in most golf shops is marked up at keystone pricing or higher, so there is definitely profit to be made if you can get some web traffic (and it never hurts to have it up for people to stumble upon).
Look up public courses in your area and figure out who the person in charge of contracting out the golf courses is. The title in my city is the "Golf Operations Manager", but this varies from city to city. Get to know this person and learn when the management contracts for various courses expire so you can put your bid in to run one of the courses on behalf of the city. This is where you'd likely end up making the most money, but it would be the most administrative of the options. You would likely be responsible for hiring, firing, reports, and other day to day tasks but the big advantage is that the city, in most cases, will allow you to use the pro shop to sell your own merchandise. This becomes huge since then the profits (or at least a large portion of them) from every pro shop sale goes into your pocket, though it does come with the added work of managing inventory and negotiating terms with the city. This is, though, by far the most lucrative option that would be somewhat easily (with enough background work and a good proposal/interview) attainable.
One other thing, along the lines of the previous point, that you could do is see if there are any professionals that are contracted to run two golf courses through the city. My city currently works this way, but the professional has to subcontract the second course to another PGA professional in order to manage everything smoothly. As a result of this the professional at the course I work for (the subcontracted professional) is now a near shoe-in to win the bid to manage the golf course he's been running when the city contract becomes available this January, just because he has been running the show there for the last four years. Continuing to excel at your current position at the golf course while networking and getting to know your customers (a large factor for the aforementioned pro is that he has developed close ties with the clientele and has increased revenue as a result) is something that will be viewed favorably if you later put in a bid to manage the course.
It took me two years to get from a 24 handicap (my starting point) to about a 6-8 handicap when I started playing seriously. It then took me another two years to get from about a 7 to a 2. In the last year I had a big jump that got me from the 2 handicap to my current +1.5, which I would consider to be the largest leap I've ever made (which is somewhat funny, considering I've probably practiced the least in the last year as compared to previous years). It just kind of clicked for me that it's okay to expect to make birdies, whereas before I felt like I never could make any.