Hey, I've been doing kickboxing for about 2 and half months now and went to my first tournament yesterday. I've done boxing for 5 years previously, unfourtuantly when I arrived there wasn't anyone my weight to fight, but after watching everyone I noticed two things that I think people could help me with?...
1) The fitness of some people was amazing, what else could I be doing outside of the training? (I use to go to the gym before doing kickboxing and bang the weights, but of course I understand that doesn't help much due to limited flexibility so was wondering what I could add in to my week to boost my fitness).
2) A lot of the people were not actually throwing a lot of kicks, even though they score more points? (I'm not sure if this was due to the contest, the competitors or if it's a normal thing? Of course some kicks were thrown but not as many as I expected considering it is kickboxing, a lot of the fighting was based on kicks.
Brief note - My style is purely kickboxing, so no shots below the waist, no knees. Purely kicks and punches.
Thanks everyone and look forward to hearing your replies and having a good chat with you all.
Sam.
To your second point; kicking well typically is less natural for most people than punching, and it takes more energy. Most novices tend to punch mostly in their first fight or two, it seems pretty unusual to see a lot of effective kicks in an actual competition unless the fighters are fairly experienced.
To improve your cardio, lots of hard bag work and sparring; add in HIT training if you can. Check out the strength and conditioning forum for ideas 
1. Above all else for cardio: Bag and Pad work. You could also jump rope, bike, hit the treadmill.
If you're gonna use weights along with bag work, then I recommend stickig with a endurance/conditiong based routine.
2. I would say that landing kicks is all in the setup, which takes a bit more practice/focus.
you want to use your boxing experience to land the kicks, throw combinations starting with hard punches and ending with kicks.