Classic French Vinaigrette.

Firstly dry some herbs - I used Rosemary and Thyme but you can use any you wish, its better to use dried as the vinaigrette will last a lot longer.
In a tall bottle add the herbs, a clove or two of garlic, a few teaspoons of Dijon mustard, a teaspoon of sugar (or honey), a handful of black peppercorns, a good glug of white wine vinegar and then top with extra virgin oilve oil.
Place a stopper in the top of the bottle and shake a few times, then leave to infuse.
When its running low you can just top up with vinegar, more oil, sugar and mustard.
The herbs, garlic pepper corns etc should last a long time before they need changing.
I often use oil from empty jars of artichoke hearts and other veg.
You can also add a dried chilli (not fresh) if you like a little heat.