I've been considering this post for a while, and rock my wedding's packing post yesterday has spurred me into action.
I am a pack-light-and-wash-your-clothes type of packer. I'm also a plan-it-as-far-in-advance-as-possible packer - Gadget, unsurprisingly, is a do-it-all-the-night-before type. There are always lists - actually there is a master list on the computer which I print out and adapt to each trip. I based it on this list which you can download (it's actually from the University of Sheffield, and whilst not perfect is one of the best I've found). Itchy feet (an outdoor retailer in the UK) also do lists for specific trips which are worth looking at through their website.
So I start with the list, then I lay everything out on the bed. Then comes the key part - I work out what NOT to take. The temptation to add things at this point is huge - I promise you don't need them. We've just been to the pacific with 24 kg of luggage between us - 8kg checked each and 4kg hand luggage. This included four bottles of sunscreen, 2 snorkels and masks, an iPad and a DSLR camera - and we still had too much stuff.
Now for the part I think is the trickiest - working out what clothes to take that serve many purposes, go with everything, are light-weight and quick drying and don't make you look like a tramp/gap year student. Particularly important for your honeymoon, when you actually want photos of you looking nice. Rohan do some good items for those of you in the UK - they look like regular clothes but are high tech so are lightweight and crease resistant. (I've got my eye on their cardigans at the moment, but I'm not sure purple is the right colour to get.) I usually have to settle for half-way decent with holiday pics, but I'm working up to 'nice'!
This recently discovered post should help. I tried putting this into practice on our pacific trip, and I think it worked. I took neutral bottoms (skirt, shorts and trousers - one of each) and brightly coloured tops, plus one dress. I left my dressy flip-flops in the UK though, so had to just use my comfy casual ones - they were fine for the no-dress code pacific (much as they are in NZ).
I also took a very minimal amount of make-up - lip gloss, mascara, coloured kohl eyeliner and a mini mousse foundation that works as a concealer too. That added almost no weight, took up very little space but was enough to make me feel dressed up. Because I felt more confident, I smiled more, and that's reflected in the pictures.
This post (provided by a RMW commenter) has some good ideas on packing toiletries and electronics. I think even I would struggle to pare down my toiletries as far as she has, but you definitely do not need the whole bathroom cabinet. 200mls of shampoo will last two people 3-4 weeks, 50g of toothpaste not quite as long. This stuff is heavy, and there's very few places you go where you can't replace it.
If you like to read, I have to recommend you go electronic. Get a kindle or sony e-reader - then you can take six books (or sixty books!) without any extra weight. I'm not going to talk about packing electronics, because I live and travel with a gadget freak and we take way too much. I'm working on it!
Finally, do not scrimp on the essentials. Make sure your passport is valid, check visa and entry requirements (do you really want to be fined £200 because you didn't know you can't bring food into NZ?) and get yourself insured. Then you can sit back, relax, and hopefully enjoy your honeymoon upgrade!