Minions aren't a big problem with Karma. Utilizing your Heavenly Wave, you can find quick ways to get the mage minions at the end, and the melee minions at the front, easily dealing magnificent damage. If you find there to be ALOT of minions, like this:
http://www.examiner.com/images/blog/EXID892/images/minion21_350.jpg

Use MantraSoul Shield to survive the rest, and kill most. hopefully you'll be able to finish them off quickly.

Not much happens at this point. yet, Karma does have low health, so try to stay out of skill range as best as possible. also, try to farm minions with MantraSoul Shield and harass with Heavenly Wave. If you can, use MantraSoul Shield to harass as well, though this may not always work. Keep in mind junglers, Master Yi,early gankers, and Jax. Karma may have alot of tricks of engaging and escaping, but early game is something you need to try the hardest in.

In lane, Karma can't survive well without someone else, so most of her abilities would work. so, though she may be good at it, I don't suggest soloing top, and try to avoid mid. Using MantraHeavenly Wave to keep them alive, and staying out of great damage. Keep in mind that Karma works better a support than a damage early levels.

At this point, you will be strongest. Though not at full build, or even much build, the enemy isn't progressing much, either. Any easy way to keep them back is MantraHeavenly WaveMantraSoul Shield. Combos like these can drive the enemy away, kill them, or become overall more effective for ganks, team fights, and quick escape.

Spirit Bond is effective when chasing. cast Spirit Bond on the enemy when chasing, but it works better if you Spirit Bond an ally when running. Mantra isn't the best spell to use for Spirit Bond, but use it when you are very low. When you have escaped, but still have high mana, Use Heavenly Wave and Soul Shield against minions to survive. Slowly, you will get back on high health.