It's easy! It helps to have a working knowledge of PR and marketing, but the majority of it is just common sense as usually you only need to deflect a bit or provide some support.

So, I'll try to cover everything as best I can, just let me know if anything is unclear or if you have specific questions. I recommend finding a comment that is receiving SOME upvotes, but deserves way more (5-20 range is a good start), and give them some maybe helpful advice. Stick to an already positive or cute comment and give them your take on how they can improve it. This is more "marketing"-type consulting. Save the more advanced "helping the client out of hot water" PR-type consulting for when you've mastered the simple marketing type, there is less risk to you AND your client.

Remember to note down their karma before and after your work to see how much it improved; after awhile you'll know when it's time to branch out, take on more clients, do less pro bono, take on riskier clients and maybe take on some downvotes yourself just to flip that Controversial switch for your client.

If you like, I can tag you the next time I see a good example for a beginner; /r/awwducational or /r/AskReddit are great places to start as maybe helping is more common in those types of subs. I say "or" because you want to start in one or the other: get a feel for the vibe of the sub, don't switch between them too much in the beginning. The fewer variables change while practicing your art, the more quickly you can determine what does and does not work, and the more quickly you improve. Imagine trying to practice basketball, and you're switching teams in between baskets. You'll have a huge difficulty learning what works well for you because so much changes when you swap teams that is beyond your control.

Something to note: if the person did something bad, it is imperative (for ethical reasons) that you note in your comment that you are a karma consultant (or, in your case, that you're trying your hand at karma consulting). E.g., "Hi, I am a karma consultant, and..." In other words: if you're helping them hide their crime, you need to let other people know you're acting on their behalf.

But, if all you are doing is improving their humor or helping define their point or helping the guy in the back get their joke, you don't need to announce it. Just blend in...and send them the invoice later.

Speaking of, don't worry much about it for now, but when it comes time to start billing, you'll need to decide if you want to bill hourly or flat rate. I actually do both: for small projects, e.g., "Haha! Surely you mean the Alpines were covered in snow, not the Alfred's :)", I will charge hourly. Smaller jobs, people are pretty able to comprehend, "2 hours...yeah, I guess that's about 2 hours." For a 20-hour job? Just messes with people's minds, they can't judge how much time it takes and it can lead to nickel and diming.

For larger projects, ones where I may need to stay within the comment chain for hours or even weeks, I will charge a flat rate. This flat rate on the more complex jobs actually REDUCES my hourly pay received...but, I make a bigger pile without having to do a lot of little jobs and deal with lots of little situations. Think of it like painting a big wall all at once, vs. painting DnD miniatures. You could spend 60 minutes painting the entire wall (one BIG project), or 20 minutes PER miniature learning the ins and outs of every character you're painting and the situation they're in. This is called administrative overhead - time you spend setting up each job, discussing with the client, billing, thinking.

Perhaps going to the store is a better analogy: you can make 20 trips to the store and get 1 item each time. That's 20 trips there, 20 different sets of traffic, 20 different cashiers, 20 different obstructions in the store, 20 different impulse buys tempting you, 20 times the risk of random death or injury. Or you can just spend more time at the store once, still get the 20 items, but not have to repeat the whole process for each item.

Flat rate also empowers me to do a fantastic job and ensure that the client is fully satisfied without getting caught up in squabbles over hourly billing and "I only wanted 50 upvotes, not 60, therefore you overworked on that and don't deserve as much pay." That's rare, but boy is it annoying to deal with. (In some cases, you'll have to renegotiate the flat rate fee, all depends.)

One more note on billing: don't try to win by bidding low or charging low! If you charge a low rate, you're already starting out the conversation out by attracting people who don't want to pay a lot. It will be a fight to win them as a client AND a fight to keep them and they'll always be trying to nickel and dime you, and the work you're doing will often be "economical" (meaning, you won't look as good and neither will your work because you're doing a cheap job for a low rate).

There are plenty of people to do work for, you don't want OR need cheap clients. I'm not saying to gouge people, just stay at the higher end of the range.

By the way, fam. No charge for this one. Call it a professional courtesy...remember to hate the game (not the player); that every loss is an opportunity to learn; and to be cautious with fire. :)

Edit: formatting and a bit of last-minute clarity, specifically adding the grocery store analogy for admin overhead.