I don't know about being "proper" but if I wish to decant in order to avoid having sediment showing in the bottle while at table I carefully pour from wine bottle to a decanter bottle (a more attractive bottle for the table) until the sediment starts to come out. Don't know if it's the proper way but that's how I do it.
After I threw this question out, on impulse, I did some research.
To decant, or not to decant...that is the question.
The idea, I guess, is to let heavier wines "breath" for awhile before drinking, to release some of the aromas. Lighter wines suffer from decanting. Mostly, it seems, it's for aesthetic reasons, and presentation.
What's always confused me is that a wine bottle lying on its side, is going to have the sediment in the neck of the bottle, next to the cork. So decanting is going to fix this, how? Duh... Stand the bottle upright for 24-48 hours before serving, so the sediment settles to the bottom of the bottle.
Of all the techniques I just read about, rather than decanting over a candle to spot the sediment in a heavy wine, I like the idea of decanting through a coffee filter! The main reason I like that is who wants to pitch the last couple ounces of a really good wine?
From “Windows on the World: Complete Wine Course” by Kevin Zraly.
He suggests decanting can be good or bad. He says old wines should be decanted immediately before service because air can deteriorate the wine. Burgundy is rarely decanted and Bordeaux is almost always decanted. Here are the steps suggested (slightly abbreviated).
1. Completely remove capsule from neck.
2. Light a candle so you can see the wine through the neck.
3. Hold decanter firmly in one hand.
4. Hold bottle in other hand and gently poor wine into decanter while holding both over candle at such an angle that you can see the wine pass through the neck.
5. Continue in uninterrupted motion until first signs of sediment are seen.
6. Stop decanting once you see sediment. Leave wine until it settles. Continue decanting.