Karma has been seen as a flawed champion because she doesn't fit her roles properly. Ideally she's a Support with a nice bulk of AP to nuke along in battle. This however is in conflict with each other. As the support role wants to feel CK''s to her lane partner and the AP nuker wants to get those kills herself. Since the nuke is not high enough for an AP caster she''ll end up on the support role and will the proceed to be not good enough at it due to a lack of money, meaning not enough stats and a lack of wards. (thanks to Stonewall) We can see she's quite the capable jungler at least at clearing the jungle but she falls short in the jungle too when it comes to ganks, her slow is reasonable but not enough.

For this build I added the 4 things karma has to keep her in the game together.

Good Shielding for support
Can build some AP without it going to waste
Has good jungle capabilities.
Map Awareness with Clairvoyance and Wards.

Add it all together and you get one of the best Counter Junglers in the game. With correct warding and Clairvoyance you can keep tabs on the enemy jungler, where he is and what he''s clearing and safely counter jungle ahead on his path. If he's on blue you can bet he''s goign Wolves and then wraiths, why not clear his wraith and double golem camps? Put that ward down at red so you can sneak in and smite that sucker right in front of his face from the bush.

This Karma build focuses on early jungling with disruption to the other team(mainly the other jungler) and support later on. In the jungle you want to use your mantra on your Shield to nuke down the creeps ASAP. When in enemy territory you can aim your Q well enough to leave one mob standing.
Once teamfights start to erupt on the map you want to be there to shield, slow and heal. At this time it might be best to Mantra your Q skill to heal allies rather then adding a nuke to your shield.

Your Sprit Bond skill is a bit tricky to use. You should try to aim it at the furthest target you can hit without overextending your frail character and try to move along as well as you can while squeezing as many allies in between you two to give them the boost too.Don't be afraid to use it on minions while going back into the jungle or to a lane that needs to be covered.

For the jungle route you buy a doran's ring and start at the wraiths. Smite the blue one and manta shield the others finishing it with your fans. Move on to the wolves and Mantra shield them too. Once the big one dies you can grab your Q and use it to kill the small ones too. Move to the DoubleGolems And Mantra your shield and use Smite to finish the second one off. Go back to base and buy 5 health pots and 2 Wards. You won't need the wards just yet but they can be placed to stop any counter jungling by the other jungler.

Move to the blue and mantra your shield properly. Smite should come off cooldown so you can smite him to finish him off. Wolves → Wraiths → Golems ending up with red Buff which you can smite again. Now you can go back to wolves to watch them respawn right when you arrive and then move down to kill wraiths and double golems again. If you did all this uninterrupted and you go back you can buy both your Boots of speed and your mana manipulator.

Remember to Clairvoyance inbetween. If you did right you can now start to counter jungle more.

Pro's.
Support and jungler in one.
Good counter jungler.
Wards and clairvoyance for good map awareness for team.
Karma can do what she''s good at rather then being restricted in a team composition.

Con's

bad ganks
requires competent team mates.
YOU NEED TO USE WARDS. Buy some ffs.
Bot lane will need something else to not get kills and protect your carry. (though 2 good solo laners and a good roamer often work well too.

Do you buy wards?

If the answer is no THEN GO BUY SOME.
If the answer is yes THEN GO BUY SOME MORE!

-As a jungling support you are important to the team but if your teammates won't do the damage needed to win the game you are not going to win. You can't do anything about this and you'll have to learn to live with it.
-This is not a beginners guide since you will have to look at the map constantly and not only see where enemies are but also predict where the ones you cannot see will be.
-wards are your friends. If a ward you brought and you placed in the enemy jungle never sees anybody it WAS worth the 75 gold as you can now cross off that route for champions you didn't see on the map.
-Spam Clairvoyance as often as you can. There is almost no reason to save it for later.
-Smite to kill things rather to harm Whether you use it to remove the first 425 or the last 425 HP of an enemy doesn't seem to matter much but it ensures your buff won't be stolen. Make use of this to steal buffs in the enemy jungle when you have wards there.
-The only 2 skills worth using mantra on are your Q (HeavenlyWave) and your E (soul Shield). Use it on Soul Shield when you farm minions/jungle but only use it on your Q in teamfights. Let your damage dealers deal the damage and focus on Supporting your own team.
-When walking back from base to the jungle or a lane you can and should use your W (spirit bond) on minions or other champions to get there faster. It is almost always worth the mana.