While I am going to write this forum from a fly fishing perspective, the same can be said for conventional gear too.
Like most avid anglers and professional guides, I am on quite a few fishing forums throughout the internet. I believe these forums are a great way to share information, get some tips, and meet like minded people. In my business, it is also a great way to meet potential clients and a "must do" in order to appear in internet search engines.
In almost every forum, the same questions always get asked: what rod should I buy, what reel should I buy, what line should I use? These may be the most popular questions in the fly fishing forums, right after, "Where should I fish?". After the question is asked, there comes an outpouring of information that can be very confusing and downright intimidating. While I have no doubt that every answer is an honest opinion by the writer, I do have a problem with 99% of the answers. Simply put, the answers are usually nothing more than an opinion from someone who likes a certain product.
While that in and of itself isn't an issue (everybody has an opinion) it doesn't help the individual asking the question. What am I talking about? How can it not answer the question if you give them an honest opinion? Simply put, you don't have enough information to answer the question. Your answer could be 100% on track, or it could be be 1000% wrong. If you are wrong, which there is a really good chance you will be, it could hinder and frustrate the person asking the question. How? Well, let's just look at an easy example.
What rod should I buy for chasing redfish? This question appears to be a simple one. However, I can guarantee there will be 100 different answers from 120 people asked. Sage, Loomis, St Croix, Temple Fork, Thomas and Thomas, Orvis, Redington, Uncle Bob's Custom Rods, the list will go on. Each person giving the answer actually believes they are giving the best answer, based on their experience. However, none of them bother to ask some basic questions before answering: what casting style do you have (fast, moderate-fast, moderate, slow, rocket-like), where will you be fishing for redfish (Louisiana, Florida, North Carolina, Texas, Mississippi or even more specific locations), what type of budget are you looking at, do you care if it is made overseas or the US, will you be traveling with it, do you want it for redfish only, the list could go on, but you get the idea.
While most of these questions may seem like they are too specific to worry about, they must all be taken into consideration when you want to give an educated answer. The rod that I use to catch redfish in Mosquito Lagoon, during winter, is not the same rod I would take to Louisiana, or the same one that I would take to North Carolina. Perhaps the most important question, that needs to be answered though, is what the individual's casting style is like. Here's the problem: without knowing them and seeing them cast, it is still an educated guess at best. I consider my casting style to be moderate to moderate-fast. However, some consider it to be super fast and others consider it slow. To make it more difficult, my casting style, like most, will dramatically change based on the needs.
So how do you answer it? Simple, I give them the same advice I give to everyone that has the ability. Go to a local professional fly shop and test cast rods. Any shop worth anything will allow you test cast all of the rods, before making a decision. When I had my shop, I would select every rod in the weight they were looking for, and told them to cast them. I told them not to look at the price tag, just cast each one a couple of times and see which one felt right. This was easier for experienced anglers than beginners. For beginners, I watched their casting stroke and helped point them in the right direction. Everyone has a natural casting stroke speed, so it isn't that hard. Yes, they'll still have to learn a proper stroke, but at least they will have a rod that matches their speed.
The same thing can be said for reels. Where will it be used, budget constraints, and most important, what balances the rod? These issues need to be known before you can tell someone which reel to purchase. Most people overlook the balance issue and then wonder why they get tired after casting for 10 or 15 minutes. A properly balanced outfit will allow you to cast all day without wrist strain, elbow strain, and arm fatigue.
As for lines, it only gets more complicated. Here, you need to know the rod, the style of fishing, where they are fishing, when are they fishing, and more. Sure, there are lines that will do most things relatively well. But, that doesn't necessarily make it the right line for the person asking the question. I have too many stories about people's trips being ruined because of the wrong line or worse yet, total frustration that made them give up, simply because they had the wrong line on the wrong rod.
What if you don't have a professional shop near you? Reach out to some fly instructors in your area. I'm always happy to let people try all of the rods I have. In fact, when I have a new client that I am teaching, I take them all, so I can point them in the right direction. This is where having over 30 years of fly fishing and being a certified casting instructor comes into play; we know what to look for and how to identify certain aspects and mistakes.
So, before you just ask a question on the forum or answer a question on a forum, take a little more in depth look. Make sure the advice you are giving is based on known information. If not, ask for more details. If they provide them, you may be able to answer. If they don't then I would avoid answering them. Then they cannot blame you for giving them bad information.