So how can we help a drug or alcohol abuser to experience the consequences of his or her behaviour?

We can help by not enabling them to escape these consequences

Usually when people are ill they need to be taken care of until they get well. They need looking after. But problem drug and alcohol users don't need this. It can kill them!
Because as long as the user escapes the consequences of their behaviour - he or she will simply carry on! Why should they want to stop? Abusing drugs or alcohol isn't hurting them!

Quite often the family or partner of problem drug/alcohol users will protect them from the consequences of their using. Perhaps you've done this in the past We're protecting them if we:
Make excuses for them missing work. Give them money or pay off their debts.
Get them new clothes or flat etc. Write sick notes for their school/college.
Try to hide their behaviour from our friends. Pay off their court fines.
  Pretend that there's nothing wrong  

We need to stop helping this person to stay sick.
We need to stop rescuing them

We need to give them some TOUGH LOVE.