Is there a best strategy for programming these?   I added the MARS mod with I believe opens up 6 meters for regular use and some of the FRS/GMRS frequencies for emergency use.  

Do you have a standard source you use for frequencies?   There used to be an Arfcom standard frequency list but I don’t know how popular that is when programming radios.  

How do you group repeaters, simplex frequencies and the like in your HT?

I have a Yaesu ft70, which comes with a programming cable and the software was a free download from YAesu. Have not messed with it yet. The reviews I have read says the older version was annoying. RT systems makes the $50 setup for this also, but I have free software and a different free cable, so I am resisting.

Do no forget to program in local simplex call channels, and the 2m adventure channel, also the ISS upload and download from the repeater, as well as the direct freqs for the astronauts. It will freak you out when you are cruising down main street and randomly realize you just heard people through are even on the ISS.

Best strategy?
RTFM and learn to do it without a computer. The time could very well come when you'll have no choice but to do it manually.

I program repeaters.

I have simplex procedures written on data sheets. Because reasons.

I have always programmed manually.

That’s the plan. The FT60r I programmed with chirp years ago.   But I couldn’t get it to cup load using digirig last week.    The 60r had different memory bald you could load frequencies into.  

The ISS idea is a good one.

Or the age old Arfcom standby, get both...

I like to know how to do it by hand and keep it documented, but it much easier to do it by cable..

JMHO,  YMMV..

The handy guide is pricey for what it is, but really really useful.

Rtsystems software and cable is the best way I’ve found to program the vx6. These days though I usually just key in the freq I want.

I like to program Doppler shift channels each side of satellite freqs.  When I made a packet (APRS) contact with the ISS it was on one of shifts between TCA and LOS.

Same.

My issue is with handheld radios is I have like 4 or 5 different kinds.  Baofeng, Radioddity, TYT, 2 kinds of Yaesu.  I can only really remember how to manually program the Baofengs and the Yaesu.

I have a herd of VX-7Rs and use the RTSystems package to program them. I did learn how to program manually, but it's convoluted and one must really plan ahead to do it well. It's also nice to be able to program multiple radios exactly the same without pushing radio buttons all day. The RTSystems control stores data into a spreadsheet format and you can have different spreadsheets for differing applications. I have even had limited success copy/pasting data from a VX-7R spreadsheet into an FT-8900R and FT-857 and vice-versa.

I have an AO in VA and another in MD, and have two different spreadsheets for the radios. To set myself up for any given area, I just select the saved data for the appropriate locale and stick it up in the radio.

Having info installed for both locales at the same time is troublesome, because repeater frequencies are duplicated (Waynesboro, VA & Glen Burnie, MD, for example) but have different tone control frequencies and it can get confusing to try to communicate with one station when your scanning stopped you on the duplicate frequency. It also extends the sweep time of the scan function if you have 25 unused (in that particular area) frequencies when you're only within range of the other set of repeaters.

I also have an emergency mode spreadsheet that puts the radios on a short list of 4 frequencies and locks the keyboard. This allows me to quickly set up 4 or 5 of the radios programmed into this mode and pass them around, with a reasonable expectation that an untrained operator won't get lost in the multiple bands and hundreds of frequencies available.

I use RT Systems.

And if you haven't seen the Tech Prepper series on the VX-6R  it's worth a watch. If you are thinking of running peltors with a Disco32 PTT the VX-6r and VX-7r are perfect for that application. Specifically because of the unique screw-in mic cable that those 2 radios use.

I used to program all my radios with hundreds of memory channels for repeaters in my region, but I go through handhelds often enough that it just ends up being a huge waste of time adapting my channel list to every radio's unique format, and expensive to buy all the custom cables and RT software. I now save a handful of my most often used repeaters manually, and then just keep hard copies of everything else on hand, and enter them by hand as needed.

I only program simplex channels that are common and repeater output's with no tone loaded. All of my radio's can scan the tone in two button presses or so, I just scan the tone if I want to transmit.

What would be nice if they had a radio that would do that automatically (match the TX tone to whatever is RX'd.) But I'm pretty convinced that the Japanese radio companies don't actual like hams, only the Chinese make innovative products any more, which is sad.