I keep reading over and over again, at various forums, the same question(s).
So here's a little precis of good technique.
I suggest using Lalvin products, not because I've got anything to gain, but because they publish more info/data about their products than any other yeast producer.
So, to start with, the basic must (must being the mix of honey and water - possibly other ingredients - to make it ready for fermentation) is just honey and water. There's a certain amount of conjecture as to what "good" honey actually is. The problem is that if it's a commercial/branded honey, it's very likely to have been processed specifically for eating/baking etc, which has a potentially adverse effect on the honey i.e. the process of heating and filtering etc, often remove some of the more subtle aroma and flavour compounds, so if possible, you not only want the honey to be pleasing to the taste, but if it's raw and unprocessed, it's likely to be worthy of the title "better". Any "hive debris" like bits of wax, dead bee's etc will fall out or float during the fermentation and clearing, which makes them easily removed.
The heating thing also applies to "cooking" the must (or wort as beer makers are likely to call it). Now there's no need to heat it up really, yes if the honey as crystalised some, then using hand hot tap water is the lesser evil. Personally, I just spoon it out the container, and then blitz it in a food processor with some water. Honey is hygroscopic, so it will take up the water quite readily. This not only mixes it well, but also aerates the must nicely. The additional water required to bring the volume up to the required level is then easily just mixed/stirred in.
Additionally, you don't need to "pasteurise" the must either. Honey is natures most anti-bacterial, anti-fungal substance. Plus with the water, well if you like the water straight from the tap etc, then it's fine to use - yes you will find comment around the bazaars that alludes to filtration of various types, both for distilled water and reverse osmosis water. Some people will bang on about those types of water not having any nutrients etc. Well if you're relying on the water for nutrients, then you're likely to be making show meads that don't use other nutrient, but also can make for a long, tortuous ferment, because one thing that honey is deficient in, is nutrients. Yes it has all the fermentable sugars you could want, but it's low on anything else. Those ingredients are normally added later.
Now with your yeast(s), the data that Lallemand/Lalvin publish, refers to grape wines, so there's still room for error, but at least it's better than nothing. It's a handy guide to work out the relative nutrient needs and with honey/meads, even so called "low nutrient" yeasts will need some nutrition. More importantly, it's handy to do a search to find out what you can, because some yeasts make good meads but have a few caveats attached. One such yeast is Lalvin D47. It does make a good mead, but it does have quite a narrow fermentation range, and it appears that it needs to be fermented below 70F/21C, because above that, it has a habit of producing fusels, that can give a very harsh, chemically sort of taste, that can take forever (if at all) to mellow out. Fusel tastes shouldn't be confused with "alcohol hot" taste because while it takes a while to mellow, alcohol hot taste will age out.
I like to rehydrate my yeasts with GoFerm. It's a type of nutrient that is specifically formulated to feed the yeast while it's rehydrating. Plus it's quite normal to use a little bit of must, some water, the appropriate amount of GoFerm and then the yeast is mixed in and it's left until some bubbling/foaming shows on the top of the rehydrating yeast.
That mix, is in turn, pitched into the must, I then either cover with a cloth or airlock it, depending on the fermenter used.
I then don't add any more nutrients etc until there's visible signs of the ferment commencing and the "lag phase" is over. I will have worked out roughly how much nutrient is needed for the batch and will have halved it to be added in 2 stages. You can break the quantities down more if you want and work out when you want to add them, though there's some anecdotal evidence, that after a certain point in the ferment, the yeast will no longer absorb inorganic nitrogen sources, so only organic sources should be used (I don't have any FermaidO, so I usually use boiled bread yeast to provide late addition nutrient).
So, I've got it mixed, I've rehydrated the yeast with GoFerm (which coincidentally, is low in nitrogen, as that can be harmful to the yeast in this early stage), there's signs of active fermentation, so I know that the yeast colony is large enough to be doing that, I've used a mix of 2 parts FermaidK to 1 part DAP (di-ammonium phosphate), which has been split into 2 doses, the first has been added after the lag phase, so now I aerate it i.e. you can use a spoon or other stirrer, but I'm lazy, so I use an electric whisk. Some people recommend at least twice a day, but I usually aerate once a day. I will test after about 1 or 2 days to see where the gravity has dropped to, as I aim to stop aeration and any further nutrients at the 1/3rd sugar break (which is a drop in gravity of 1/3 when the starting and estimated final gravity have been worked out e.g. if the start is 1.090, then the 1/3rd break is at 1.060, presuming it's finished at 1.000). I will always aerate first, before adding the final nutrients as that can cause the mead to let the CO2 out of solution quickly causing it to foam into an eruption, which is less likely if most of the CO2 has been removed with aeration/stirring, and you get better eruptions from carboys than you do from buckets......
Now, if I'm making a "Traditional" mead (honey, water, nutrients, etc), I will usually ferment it dry and then back sweeten it. I like my meads sweet, but not too sweet. Some of the commercial meads I've found and tried here, have all been too sweet and when tested have a finished/final gravity of up to 1.040 - which is cloyingly sweet for my taste. I like mine at about 1.010 to 1.020 and I like to sweeten them with honey.
This is potentially problematic, because the addition of honey can cause an already cleared mead to haze. So I let the ferment finish (finish is after I've had 3 identical gravity readings taken a couple of days apart over the period of a week). I will then stabilise it, which is done to prevent any refermentation starting. I will rack the finished mead onto 1 crushed campden tablet per gallon and 1/2 a teaspoon of sorbate per gallon (sometimes called potassium sorbate, or wine stabiliser). Then while it's still cloudy, but after a couple of days, I'll add a 50/50 honey water syrup up to the required gravity level, the exact level is achieved by taste but also with hydrometer tests. Once it's there, then I'll just clear it with racking and time, any topping up needed is done with either another mead or with vodka. If it's not clear by the time it's aged for 12 months, then I'll use 2 part finings.
That's not perfect practice/technique but it's not a million miles away from the methods suggested in the excellent Gotmead "NewBee Guide" either. It's linked so you can also read it if you want to.....