Your operating position

Once you have your antennas set up, coax feeds run, and your operating position set up, it will be down to you and your radio. The selection of the particular radio to use is a very personal decision, of course, based on the collection of preferred features, its interface, size, or even just a sense of trustworthiness and reliability.
In my view, the main interface to your radio is not the front panel with all the knobs. I believe the primary interface is the sound going in, and going out of it. The DSP, compression circuitry, filters, and other mechanisms inside the radio all work together to render the HF signal to AF. What happens next is up to you.
I am an unabashed Heil Sound fan. I had been using either the Pro-Set Plus or Traveler Dual headsets exclusively. I've added a new headset to the mix recently after trying it at the K1TTT superstation. The Pro-Set Quiet Phone is a headset with all the great stuff in Pro-Set Plus like a superb microphone element and a comfortable feel on the head. It also has noise-canceling circuitry that was very impressive in the K1TTT multi-operator environment. It only took about 15 minutes of operating with these beauties to convince me I needed a set for myself.
I used my Pro-Set Quiet Phone headset in last weekend's New England QSO Party. Like last year, I was using my Elecraft K2 running just 5 watts so having good audio is very, very important. In fact, out of the 39 contacts I made the contest (I was preoccupied this weekend) no fewer than 5 guys complimented me on my audio.
What my K2 is missing is a voice keyer. One of the reasons I didn't put more hours into the contest was because I was losing my voice. The internal voice keyer inside the IC-7000 had spoiled me! Keyers, both voice keyers and CW keyers, are indispensable tools for an extended operation. Of course you can say your call sign. Of course you can squeeze the paddles and send your call sign. The trick isn't to do it once or even 50 times; the trick is to do it 5000 times over an extended period.
For CW I have the microHam CW keyer which provides both CW keyer functions and rig control function with its USB to serial / CAT interface. The best feature on this unit is the big, round knob on the front for the speed control. You know, sometimes the best interface is the big knob that just does the right thing. I brought this unit to Montserrat and it performed very well. Most logging programs have some facilities for triggering the keyer memory. I developed an add-on for MacLoggerDX called FKeyer for this purpose. Yes. Being a programmer does occasionally have its advantages {grin}.
Voice keyers seem more complicated, but they shouldn't be. I have owned the MFJ 434B Voice Keyer for a while but have not set it up yet. After this weekend's wear-and-tear on my voice, I'm now motivated to get this device working with the K2. I wonder how much current it draws? It would be very nice to have a voice keyer on Georges Island (and Lovells Island for the IOTA contest). The new Elecraft K3 offers a voice keyer option, too. In my view, if you operate SSB, this is a mandatory component.
Finally, you need some way to key the transmitter. I have tried and tried but I just can't find the right combinations of VOX settings that make VOX usable for me. I prefer keying the transmitter though mechanical means. If at all possible, I'll use a foot switch. I've posted previously on how to find a nice lightweight (and cheap) foot switch for this purpose. I found that there are times, though, when using a foot switch isn't the best option. When operating portably with nothing but dirt (or sand) beneath my feet, the foot switch can be difficult to locate with your foot and even harder to trigger. I had built a hand-switch from junk box parts and it worked. But, Paul "Lava" Van Dyke (VP2MVO) had a Heil HS-2 hand-switch on Montserrat and I was foolish enough to give it a go. It felt very nice in my hand and was rock solid (like the rest of the Heil offerings). So, I now own that, too. It lives with the noise-canceling headset and will be used for all my portable operations.
It is less important to have the foot switch if I am not computer logging. If I am paper logging, I can write with one hand and use the hand-switch with the other. (Of course, using that strategy, I should really learn to manage the paddles with my left hand so I could write with my right. I'll put that on my New Year's Resolution list next year!)
Your operating position, your radio, headset, foot switch, keyers, and even rig control all combine to give you your presence on the air. If these elements work together and are comfortable to use then you'll be able to operate for hours at a time, days on end, and fill your log book with lots of nice QSOs. But, if you've not thought through these things, if the operating position is uncomfortable, or unoptimal, you will expend energy to overcome that deficiency while you operate. Eventually, you'll tire (or your voice will tire) and that ever valuable Island Time will be wasted.
My advice, obviously, is to consider all these things the next time you evaluate your equipment. To use a running analogy, you can't run a marathon with a rock in your shoe. Work out all these things prior to your trip so operating is a pleasure--and a breeze--on your DXpedition.