I travel very frequently with type 1 diabetes.
Most of what you do will be the same as back home as long as you remember to take everything with you.
Packing for my trips often starts with me sitting on the floor counting out needles, lancets, test strips and dextrose to make sure I have enough to take with me. It maybe worthwhile putting in an extra prescription to make sure you have enough supplies to cover you.
I always take twice of everything as I think I need. This includes taking back up pens. If you do not have any spares, this is something to request from your DSN.
In addition to the items mention in the JDRF link from
@noblehead, I always ensure I have an official letter explaining that I have diabetes, must take my supplies on the plane and that includes sharps. In fact, I get a little soupcon of joy answering "yes" to the question "do you have any sharps in your hand luggage?".
JDRF suggests splitting your supplies. I avoid this as the letter only says that I am able to carry sharps. Maybe different for children (which JDRF focuses on ... although they have a little bit of adult stuff).
I use Frio bags and have found them fantastic from Ghana to Greece to Venezuela and beyond.
They are not your usual insulated bags that you would put food in. They work by infusing crystals with water which transforms them into a gel which releases the water slowly ... and keeps the insulin cool.
The only word of caution is to hold off soaking the bags until you have landed. I have heard of some over eager security guys getting concerned by the use of gel.
One common question is "what do I do with my sharps?" If you are incredibly lucky, you may be able to dispose of them at the resort. I have never done this: I put them into a small (empty) water bottle and decant them into my sharps box when I get home.
Being on holiday, your usual food, exercise and, maybe, drinking regime may be different. Therefore, you may need to keep a closer eye on your BG which can also be affected by the heat.
Above all, have a great time and don't let diabetes change what you normally do on holiday.