How do you stay motivated during cardio?

I get bored with steady state cardio as well (like the elliptical or treadmill), so I never do it. I am good with weights, so I like to set up circuits for myself that I do at high intensity with short breaks in between. For example, yesterday I did 3 sets of a circuit that started with 10 wood choppers on each side, 10 goblet squats, and 30 seconds of mountain climbers. I do them as quickly and with as much intensity as I can while maintaining good form. The weighted exercises are not quite at my max but are still heavy enough that at the end of the set I could probably only get one or two more reps in without fatiguing. After each set I take a quick break to catch my breath (Just long enough I'm not gasping for air, but I'm still feeling pretty exerted), and repeat.

With this approach, I'm generally too busy gasping for air to get bored. At least for me, this has yielded better results (in terms of a reduction in body fat%) than when I was doing steady state cardio.

I mix up the specific exercises (I usually do two different circuits with 3-4 different exercises per gym day and try to mix it up so most parts of the body are hit with the weights), but here are links to the examples I gave in case you or anyone else is curious.

woodchoppers: https://www.youtube.com/watch?v=pAplQXk3dkU
goblet squats: https://www.youtube.com/watch?v=PKmrXTx6jZs
mountain climbers: https://www.youtube.com/watch?v=DyeZM-_VnRc

Sometimes I play "Killing In The Name" by Rage Against The Machine on repeat until cardio is over. That usually helps.

May sound weird, but not thinking is what motivates me. Or in other words, feeling my body and surroundings is what keeps me going.

Overanalyzing and overthinking were never a good thing. Stop thinking about cardio this, cardio that, and you will enjoy it.

Thinking and feeling are highly exclusive of each other.

I found cardio that I actually liked doing. For me, that meant not on a machine.

I found cardio that I actually liked doing. For me, that meant not on a machine.

This. And since you like lifting, I recommend trying some sort of HIIT for your cardio.

Personally, I like hiking for the scenery. Can't give up when you're half way done that way haha.

Like everyone else has said, try to find cardio that you like. I like working out on the elliptical, but I have to have music. Most of the time I remember to sing along silently if I'm at the gym. Most of the time.

I pretend I am training to be a superhero >.>

^^This! Also, listening to audiobooks in itunes on the phone can be great, although I sometimes find myself going slower just to drag out the amount of time I get to listen to the story...maybe not the best plan, but I'm definitely never bored.

Get outside..breathe in the fresh air and nature let your mind wonder freely. With intense cardio..Just keeping up is motivator enough for me.

First off, cardio doesn't do too much for body composition, bar let you eat more (which does help me, I like food.)
However, it does have various other benefits, so I consider it worth doing myself.

For running, I find it really helps running with others - look for a local running club.
For cycling, I often 'cycle for cake' just doing daily stuff - to and from work, to the shops and so on.
On a weekend day I'll easily do 30-40 miles in total going around the place running errands etc. Panniers and carrying shopping means a few more calories burnt . And, because I can lock the bike up right outside the shops, miss out section, queues and so on, generally I find I don't take massively longer than if I'd gone by car - Maybe I'll, say, spend 3 hours travelling rather than 2 hours, but I'll also get 3 hours worth of exercise for spending one extra hour on, which is a pretty good deal I reckon .

This sounds really silly, but I daydream as I listen to music and do cardio. I just make up some scenario and play it while I run, go on the elliptical, walk, and so on. I suppose you could daydream about anything you wanted to, lol. Mine usually just involve traveling, meeting new people, and me being super cool and badass.
It helps I promise hahaha

This.
I'm climbing the Grand Teton late this summer, and I need the cardio for endurance purposes. I get lost in a daydream about just how freaking awesome it's going to be to power up Garnet Canyon with a packed 65L multi-day on my shoulders, and NOT be dead and gone when I finally climb up the fixed rope and set up camp on the lower saddle.
Rocking and rolling in the back country is my favorite day dream.
And also hot men play in the back country. ;D

Set goals when during your cardio workout. i.e. My first goal today was to run 10 minutes and once I reached that goal I walked at a rapid pace for 1 minute. I did that 3 times and before you know it I had run 33 minutes. Next week I will up that to 12 minutes and so on.

Fast pace music and a tv.

I use the timer on my phone. 45 seconds of hard fast resistance on the cross trainer.. Then 45 of easy speed. I am only doin 12 min of cardiovascular work a day to begin with and weight training the rest of my time in the gym. Any how today my 12 min went so fast.

This sounds really silly, but I daydream as I listen to music and do cardio. I just make up some scenario and play it while I run, go on the elliptical, walk, and so on. I suppose you could daydream about anything you wanted to, lol. Mine usually just involve traveling, meeting new people, and me being super cool and badass.
It helps I promise hahaha

I honestly do the same thing. I have lost about 80lbs and I have been away from home for a long time. So I will plan and daydream. I think about how skinny I'll be by the time I get home and see everyone. I think about the outfit I want to buy when I reach my goal. Or, much like above, I'll just daydream ridiculous scenarios... haha

So funny about the zombie proof house.
That's one of the things I daydream about.