At the end of every scaling ( cleaning appointment) we usually take out time to talk to the patient about oral hygiene. Ask about their technique - correct it - recommend stuff etc.
The one question we invariably get is - DO I NEED TO FLOSS? (We shall not even go into the 'Floss? What's floss?' category of patients.)
Contradictory to the answer we give when the patient asks about using mouthwashes (which is it varies patient to patient) - the answer to this question is YES YES and YES.

If you can and are willing - Do IT.

Why you ask?

Well, lets just take an example to understand this.

You have a bed at home. You clean on top of it. You clean the sides of it. However the bed is rather low and you cannot get under the bed and hence the underside is left as it is. Now being good quality wood and all - maybe it may never really get ruined. But suppose there was a leak - water got into the room and under the bed as well. Now don't you want to move that bed so that you can dry the floor beneath? Better still, don't you empty it out and take it outside perhaps so that you could dry the underside of the bed itself? 

Of course you would - given that you don't want fungus growing out the bed. 

Now our teeth have 5 sides as well - and though with meticulous brushing we can clean 3 of them - 2 sides are like the underside of the bed. While nothing much accumulates there most days - there is always the risk. 

It would be lovely to get those teeth out - wash them in the sink and put them back. But since that isn't happening anytime soon ( unless of course you prefer dentures) - we have to make do with what is available to clean out those surfaces.

Food does get stuck between teeth - even if its not a big chunk - it will be a thin almost transparent layer. Moreover when we are young contacts between teeth are tighter. As we age teeth start collecting more and more food particles making flossing all the more essential. 

Yes it is inconvenient (But you get used to it)

Yes it is time consuming (But you get faster with regular use)

Yes it involves putting your fingers in the mouth (But you can always use those floss handles)

But given that it decreases your trips to the dentist - what more motivation could you possibly want?

There are a zillion different types out there - choose any one based on your convenience and budget.

Use it everyday, once a day.

Ask your dentist for a demonstration of the correct technique.