Forever, I loathed water, couldn't drink it at all without cordial in it. I used to take packets of Tang on school camping trips, and carry my own massive drink bottles, because I could drink the plain water. So here's how I came to be a lover of water, and it is literally the only thing I drink now (save alcohol LOL).

I started drinking natural cordials, and then began watering it down. Bickford berry cordial goes nicely into 4 litres of water, then it was 5, then 6... Bickfords Lime and Lemon & Barley are nice too. They are MUCH cheaper than flavoured Pump rubbish, about $6-$8 from any supermarket.

I also bought a Brita filter jug. Costs me $12 every 3 months for the filter from KMart, a little more from Coles. I still can't stomach straight tap water - and WA water is worse than Melbourne! I refill my water bottles in the fridge from it.

It is much easier to stomach, I found, if it is really cold - so keep it in the fridge.
Start with 1, but work up to 2, full glasses of water FIRST THING in the morning. Not only is it fantastic for your gut health and metabolism, it also gets 500ml out of the way before you realise what is happening.
Coffee is a diuretic - it makes you pee more, and strips hydration from your body. Not helpful. Every time you drink a cup of coffee, skull a full glass of water before hand. Every. Time. Coke (being full of caffeine) will not be helping.
You will get craving for the sugar. I still get them. For me, it is lemonade, not Coke, but they do go away for the most part.
Skull a glass right before bed - work up to two - it will help you sleep better, will make you feel better in the morning when you wake up, and before you know it 1 litre of your water intake passes without you noticing, simply by drinking the 2 glasses first and last things of the day.
Get a 1.25 litre Pump bottle. Fill it once, and carry it with you wherever you go all day, all round the house, the car and when you go out.
I preferred to have big skulls - can't taste how **** it tastes that way LOL, but you might be a sips kind of person. Either way, it is habitual more than anything. I can't function without water now, I cannot even begin to understand how totally dehydrated I was before. I didn't even drink water on shift. Blergh. I *feel* so much better now! My skin is better, I have more energy, brain works faster, it is quite amazing. I go without water for even a couple of hours, and I feel like crud.

So, total reformed water-hater over here, and that is how I did it. There are still days when I have to force myself to drink those first two glasses of water, but I know that I will feel better for it. I still get days when all I want i lemonade - so I buy can and realise I love it, but it just makes me more thirsty anyway. And I still drink coffee - but I don't *need* as much, because I am actually hydrated and have more energy without it.

Bickford's. Best. Stuff. Ever.