Let’s talk about sound, and keep it simple.
A few ways to go here. And your choice of mic’ing is situational.
All of this is about what you need for the situation. Interview? Selfie presentation?

If you are doing an interview, or letting only the subject  talk, A directional mic like the Rode VideoMicro is a great choice, as there is no need to attach a mic to someone.
Best when you are doing an impromptu street interview.

In the same size realm Deity makes a similar mic that allows you to have a “back” mic. In other words, when in an interview situation, you can record your voice, as well as the subject equally. This is an adjustable switch on the mic to be one way or 2 way. With this mic, you can have a good mic pattern (looks like a heart on the mic) on the subject, and also have your voice clear on the video. That rear mic feature can be turned on and off.

The advantage of either of these kind of mics, as opposed to no mic, is that you have minimized the extraneous sound and concentrate on the subject.

The next option is when you want to put a mic on your subject for higher quality audio.
In this scenario, you have engaged your subject, and can properly attach a mic to them.
It’s a bit of a personal space kinda question, because attaching something to someone, requires bigger interaction.
One thing I have done is ask the subject to clip the mic to their clothing, or when using a lav, clip the lav onto a collar or button row, and put the transmitter in their pocket.

Here are the 2 systems I recco. Both of them will yield great results when set up properly.

Both have adjustable sensitivities ( or DB ) , so make sure you have tested and found the right  basic set-up for you. I have my mics always prepped to put on someone, and start recording, as I also cover trade shows, and it’s usually a similar situation as I interview going from booth to booth. Yours may vary.

The AnkerWork mic system M650, comes with a charging case, 2 mics with mags and clips, and changeable covers depending on the clothing you are attaching to.
And as mentioned, you can add your preferred lav with a cable, while putting the transmitter into a hidden place, and wiring the mic to your subject. Or yourself.

With this system, you can plug the received directly into the phone, whether it’s lightning or android! Very helpful. And you do not need to remove or modify your case! Whew!

So with this you can also monitor the recording from the receiver.
An advantage on the Ankerwork is that you can plug the receiver director into your phone, IOS or Android. No additional wires needed. The plug into the phone also lets you keep the case on, as it has the length.
While the Ankerwork you have a magnet system for the mics, so you can either clip the mic to clothing , or us a magnet to clip the mic to clothing.

A very popular system is the Rode Wireless Go family, and you can also have 2 mics and the receiver plugged in. The latest version also has a compact charging case.

The Wireless Go II also has 32 bit float, meaning you have a protected recorded track that allows you to adjust any peaks in the record. This is useful when you are adding the audio when in an edit.
If you are simply recording/editing/ and posting via your mobile device, it is not a feature you need.
This familiar square system uses a spring clip to attach the mic to clothing, and the receiver slides onto a cold shoe with a similar clip. The cables you need are included in the package.

With Rode, to make the mics or receiver magsafe, you need to add a $20 add on for each part. Basically, a metal piece that goes into the clip and a magnet that holds it in place, through fabric or, what I like, is putting the receiver onto the camera back using magsafe.

I have used that magclip add-on and it works on my phone, and you do need to add a cable to the phone.
You can also add your fave lav mic to this set-up as well, by plugging it into the mic transmitter.

I go to Sanken or Tram mic for either system. Please note that you may need a converter for higher end mics. Of course the Rode lav will work.

More info on that here  In the Rode system, you can monitor the recording using a wired headphone on the receiver. BlueTooth can only be used in playback.
Only issue I have with both systems is that they insist on having their brand name on the mic facing camera. Please stop.

Here is what the various configurations look like, using the Snap as a grip:

First is the Ankerwork M650, which is more streamlined.

Here is the setup, with the Rode VideoMicro. Same look with the Deity. Needs proper wiring to phone. SnapShoe gives you the place to add the mic.

And the Rode Wireless Go II. Also needs wiring to the phone.

To be fair, Rode does make a version of the VideoMic called the ME-L. 

Connects direct to the phone but the lightning connector is too short IMHO. You will need to trim our phone case for it to fit securely. I know, seemed like a great solution.You could add an extender without cutting up your phone case, although, I would still be concerned. They suggest not using a case at all, jusy not my preference.

Another option, depending on subject distance, is the Rode NTB mic which will work, although the larger grips like the Beast or the Small Rig, may be better suited to that longer mic. It also can be fed into the phone with an appropriate cable IOS, or Android.

All of these mic solutions will work great with your mirrorless and straight up video systems as well. These featured here are looking at smaller, and lighter footprints.