I have a USB interface into which my mic and headphones plug. it operates as a mixing desk so that I can adjust the volume but it doesn't have tonal adjustment. I have it so that I can plug in a guitar and a synthesiser as well as the mic.
It's a Behringer U-Phoria UMC404HD and I've had it two years during which time it hasn't worked, for this purpose, at all. It's been back to the shop and it's been reported to the manufacturer. And still it sits, performing no service except as a one-way traffic interface/preamp to let me play from the PC to my amplifier.
So from the point of view of recording my BLOG/casts, it's an ornament.
Instead, I record into an Olympus digital recorder, plug it into a USB port on my PC and transfer the files. This, oddly, has an advantage because I can drop the recorder in my pocket and then, if I want to, I can walk around as I record. This simple approach makes high quality MP3 recordings.
I know that some people use a headset (either wired or bluetooth) to record to their phones. If that works for you, that's fine: after all, it's not dissimilar to my Olympus except in one aspect: phones make all kinds of noises and suffer from interference. So this only works if you make all those selections that turn it off so it's a recorder and not a phone for the time being.
Of course, if you record rubbish, you get rubbish out, so the input has to be good. That's where the variables come in and most of the variables are due the shortcomings of the soft machine. (1)
There are several basic types of microphone but the first decision - and perhaps the most important - is whether you want a directional mic or one that picks up from a wider arc.
Directional mics have a narrow "sweet spot". They are no use if you move around in your chair: you will go in and out of range even as you swivel or reach for something across the desk.
A boundary mic (do not get a boundary mic: they are for conference rooms) picks up everything within its range, in all directions.
In between there are many options.
A mic is a personal choice. Go to a shop with lots and try out the different types.
You will need to think about where your mic will be, relative to your mouth.
A stand-mic sits on the table. It picks up all the vibrations from the table.
A mic-stand sits on the floor. You can fit the mic to an adjustable boom and position it as you like. But it picks up vibrations from the floor although in most environments this won't be a problem.
The last thing is a device that attaches to something like an Anglepoise lamp and you can adjust it. Mine is clipped to a shelf next to my desk but not actually attached to the desk.
The best stand mic in the world is no use if you can't sit in its sweet spot for the whole length of your recording. Those American TV shows with a stand mic on the desk? They are just for visual effect: the participants are "mic-ed up."
You don't need to spend much to get one that is good enough and, if you decide you want more, you can buy something else later.
I did, at first, try using an excellent Audio Technica stand mic with a USB connection directly into the PC. But I don't like sitting close to the mic and if I was more than six or so inches away, it didn't give me enough priority. And I found that I fidget a lot and kept touching the desk and the mic picked up vibrations.
So I set out to hunt down the mic I had used in studios in the 1970s and 1980s. It's called the AKG Sound Rocket. It took more than a year and it was my son, not me, that found one in the USA. It is in remarkable condition with barely a scratch and with exactly the sound profile and performance I want. With luck, sooner or later, a flood will come onto the market because the British Houses of Parliament is still using them. Sooner or later someone will make the silly decision to spend money on something newer. They shouldn't. I took mine apart to see what condition it was in inside (perfect: it was obvious no one had ever opened it up before) and stupidly pulled a wire out. The local AKG dealer was sitting using it when I went to pick it up from repair. " There is nothing this good on the market today, " he said. My son, who has a collection of vintage mics including several from the USSR which are rough to say the least, says that today's mics, developed for digital, don't have the warmth or depth of the old mics designed for recording to tape.
The choice of mic is, then, important.
But you don't have to go to great lengths. If you speak at conferences, you know that those little clip-on mics give good sound. Clip-on mics are actually very cheap and, so long as you put them in the correct place, really do a fine job if you connect it to a digital recorder. But a word of warning: they aren't great if you are sitting down and fidgeting because they pick up movements through the wire.
Headphones matter. They are useful for when you are recording but they are essential when you are editing. You need to be able to hear background noise because even if you don't notice it, your listeners will. Remember that many of your listeners will have earpieces from their phones and while the sound out of most phones is terrible, sounds that shouldn't be there have a tendency to stand out.
Mine are some nice Audio Technica bought specifically for the purpose: they have wide responses and resist distortion even when "pushed" and equally importantly they are really light. I tried several others but most had fatal flaws. Incidentally, my beloved Bose noise cancelling headphones which are my constant travelling companion aren't so good for editing.
A caveat: many headphones today have a mic built into the cord. Don't use it. It's fine for chatting to your mates while you are playing games or making video calls. They are not good enough for making broadcast recordings.
We'll look at recording and editing software on another page.
(1) "Soft Machine" is the title of a book (William Burroughs, 1961) - see https://www.penguin.co.uk/books/576/57604/the-soft-machine/9780141189789.html . Ultimately, it refers to the turning of humans into an extension of machines.