Step 1: Define your goals

One of the first things a hobbyists will want to consider is what do they "want and expect" from a planted tank? There are a number of general methods, and newbies often get confused due to seemingly conflicting advice.

Why is there conflicting advice to begin with?
Plants and planted tank methods vary, this is good!
What might be good and attain one person's goal, might be total pain for another person or seem boring to another. Adding to this dilema is that most folks that give advice believe that their method is best for them, they may well be right there, but that does not imply that it's right for you!

Also, most folks that are successful at a method tend to stay in that "safe zone" and rarely try other methods. Some virtually never seek new methods or master the ones that they have failed at in the past, they argue that if it works, "why fix it or meddle or try and improve"? I suppose we could say the same about living in caves and not really needing the Wheel if we followed such logic.
Still, a person can only discuss fairly what they have mastered without bias, you must be successful at a method to give advice on it.

We assume that all methods are successful with various trade offs. So the failure aspect is really due to us, not the method. Sorry, cannot blame a method, only yourself, we like to blame other thigns than ourselves often times, but that is social science, not plant science

Much of this stems from the issue of using CO2 gas or not, or sometimes Seachem's Excel. Adding CO2 gas increases the growth rates of plants about 10-25X. Adding Excel about 2-4X.

Good fast plant growth is general what many want...........till they realize that they have to prune often and have more troubles balancing adding fertilizers and CO2. This can be addressed by using slower growing plants, not using high light(huge mistake in general for most plant hobbyists, more light is not better, it's just more work, that's fine if you enjoy it) and using driftwood and rocks in your layout(they do not need "pruned"!)

Non CO2 enriched plant tanks are very nice also and very easy to care for if you can adhere to a few simple rules(A must for success) and not over stock the tank. Growth is slow, but the trade off is that you do not have to do much work and still can have a nice tank.

CO2 enriched tanks do not have to be high light, this is a very bad assumption that many hobbyists make. A combination of moderate to low light provides and far easier routine and affords much more wiggle room if you make a mistake or neglect anything.

Light drives CO2 uptake, so more light= more CO2 demand by the plants.
Getting good stable CO2 concentrations at higher light intensity can be a real challenge. More is not better.

Nutrient sources come from 4 main possible areas: fish waste/food, inorganic fertilizers such as KNO3, Iron etc, tap water(may have PO4 and/or NO3) and sediments such as soil or various commercial products like ADA aqua soil or Flourite from Seachem.
Some argue for plain old sand, that works also and can grow most any plant too.

In slower growth tanks, any one of these might be able to supply all the nutrients, demand is low, adding CO2 increases that demand and the growth rate.
Adding more light increases that demand and growth rate.
Thus at higher growth rates, all the fish waste is quickly consumed as the tap's nutrients maybe as well, we may chose to add fertilizer to the water column or the sediment or both locations.

The main point here is that as growth rates changes with various methods, they rules also change and the trade offs afford you more or less options.

Differences in growth rate cause perhaps the greatest confusion and appearent conflict in the advice for methods that's given on the web. The poor newbies wonders off wondering who is right. Most folks that give advice tend to use one or two methods without really understanding how each of the other methods work. They are successful with one method that suits their goals and they stick with it.
After awhile, they might try another method, I fully encourage exploration there. It makes you more well rounded as an aquatic plant hobbyists and allows you to offer more methods to other folks starting out later on.

There is no one method that suits everyone, some have suggested this, but it's clearly not the case, all you need to do is look to the CO2 or not to add CO2 to see clear cut differences and goal trade offs.

You can use less light or more, use no CO2 or high CO2, higher nutrients, or verty low nutrients, the water column for dosing and or the sediment.

It's much more up to your goals, so clearly your goals are not defined by any one method there.
So when you get bombards by all sorts of advice, keep a clear head and stick to your goals!

Focus on those.