Stop spending money you don't have.  Pay your financial obligations on time.  Reduce or eliminate debt ... just stop buying crap you don't need. 

Just. Stop. It!!!!

A trusted loan/mortgage professional should be consulted. 

I am not a credit expert and refer to someone who truly knows. But. Paying those bills on time and keeping your balances low certainly helps

Talk to their lender and get the proper advice from them. Daniel Lloyd you are leaving yourself open to law suits when you give advice outside of your own wheelhouse.

 What Bob "RealMan" Timm said. 

No, we don't do it.

My best advice is "meet your financial obligations in a timely manner".

I leave additional advice to lenders. They are closer to the nexus of this subject.

I have always lived by what Kathleen Daniels said.  Pay credit card bills on time and in full.  Treat the card like cash and don't buy what you can't pay off that month.

For paying off debt, the program I like is:

1. Gather up all your statements and add up your total monthly expenditures. 
2. Determine the order you wish to pay the bills off in (quickest, largest principal, largest interest).  Consult advisors for assistance on choosing an order.
3. Take the first one on the list and add additional monies to that to pay it off the principal quicker.
4. Once that is paid, take the money you would have spent on that bill and put it all towards the next bill on your list.
5. Repeat step four until all debts are paid.

That's the simpliest way and how I'm tackling my mortgages.  You can also add in negotiating a loan reduction.  Beyond that, lenders have more ways to fix credit.  The few clients I've had that have needed help in this department have gotten free assistance from their lender.  There are also paid credit repair agencies out there.

The easiest & quickest way to improve credit scores is by paying down revolving debt (i.e. credit cards), as these ratios account for 30% of the weighted credit scores for the 3 credit bureaus. 

Rather than putting your neck out and potentially giving bad advice blindly, I'd recommend contacting a Lender who can perform a "What If Scenario" analysis to determine the specific impact to the credit scores by paying down debt (i.e. how much, to what card(s), etc.).  From there, your Lender can perform a "Rapid Re-Score" and boost the credit scores accordingly. The technology is surprisingly reliable when used correctly.

If your Lender does not provide these credit boosting strategies, I am happy to offer my services if you need a resource (although this answer was not designed to "solicit" any business).  

Lastly, if you'd like more information about how credit scores are computed, you are welcome to click on the AR article below. Despite being a few years old, the majority of data is spot on to today's scoring algorithms.

https://activerain.com/blogsview/1896723/how-are-credit-scores-computed-

Hope this helps!

Biggest? Pay on time.

Pay your debts on time.

Bob "RealMan" Timm Has the best answer.  Good luck in your studies, Daniel.

Paying your credit obligations on time is a great start.

Daniel,

Although we may have tips, the smart thing is to keep your mouth firmily shut, and let a lender advise your clients...unless you want to be faced with a lawsuit.  A

I know someone who does Credit Repair & is very popular up here. I just recommended him to a client. She had done a short sale awhile back with me & recently I got her into a Rental (with the addition of a Cosigner on the Lease). Hopefully he can make some good suggestions, Credit Repair isn't my forte. 

I agree with Kathleen Daniels 

Pay down cards to less than 69% of line. 

NEVER close an account.

Pay on time 

The best is to not do anything until you talk with your loan officer.

Removing all derogatory inaccuracies.

The best tip - talk to a lender or credit consultant.

SHORT TERM

STOP spending!

That means the account balance increases.

LONG TERM
Don't close accounts but never exceed 60% of limit. Creates great credit and these accounts can be closed when necessary.

Make payments on time!!!!

Pay on time.

we don't get involved with the details of anyone's credit issues....we direct them to a well-versed mortgage officer....

No idea. 

Pay your bills?

There is a formula to manipulate for this, however some of the wealthiest business people I know do not play the game and have mediocre scores.

The tips coming from my trusted loan officer!

I don't provide credit advice. I'm not a credit or mortgage specialist. I provide advice on buying and selling homes. But everyone should know to live within their means and to pay their bills on time. They don't need to hear it from me.

I leave this for the professionals.

Helping partner a buyer with bank to repair their credit happens a lot. Best tip for borrower wannabe is to do what the loan arranger wearing the mask tells you to not what you the never done this before buyer thinks would help. IE Has cash and pays off  a bill thinking it would help and instead should have done something else with the money. When approved, don't get divorced, don't change careers, don't buy a new car or boatloads of furniture for the new home that debt ratios suddenly swell too high and keep you from buying. Wait until after the closing when you are approved for a loan to make those moves.

Plan all your expenses and payments carefully, have a strategy to deal with whatever you are facing.... 

Don't use credit...period!

Pay bills on time

Talk to Credito reparar guy.... 

Working with a professional.

I don't give credit counseling but refer them to my lender that has a credit counseling program.

I refer them to someone who does this full-time.