If the weather is hot, chill the reds. Remember that reds are served at European room temperature which is about 18 – 20° Celsius. If you think that your most of your guests will appreciate slightly chilled reds but there may be a real traditionalist who objects, then don’t let him see you take the red from the refrigerator. Don’t serve it too cold though!
There is a general order of serving wine – lighter tastes before richer flavours. Hence whites before red. Riesling before Chardonnay; Pinot Noir before Shiraz. Light wines match lighter flavoured foods, and similarly fuller flavoured wines are best with rich foods. Food dishes often follow this principle – a light taste such as soup or seafood before a meat dish – but not necessarily. Within reason it is quite OK to serve a fuller flavoured wine with a strong entrée dish, and then revert to a lighter wine with a lighter following main course. For example, beef carpaccio with olive oil and grated parmesan cheese is a full flavoured entrée and would be well matched with a Pinot Noir. This might be followed by white fish fillet and be accompanied by a light white such as Riesling.
It is quite OK to serve the next wine into the previously used glass, particularly if the host owns a limited number of prestige glasses and they need to be re-used in order to cope with the numbers of wines being served. Often the glass needs a rinse, and it is acceptable to tip a little drinking water into the wine glass, swirl it around and swallow it – leaving the glass rinsed for the following wine to be served.