Paraguas y lluvia

Eight as a minimum. With six, the fabric bags between the ribs and the wind catches it; with eight, the tension is spread much better. Golf umbrellas usually have ten or twelve, which is why they hold up as well as they do.

Fibreglass over steel, because it flexes and springs back instead of staying bent.

One with a double canopy: it lets a gust escape through the top vent instead of pushing against the whole canopy. It's the detail that separates an umbrella that lasts one winter from one that lasts five.

The folding one fits in a bag and is what people actually carry with them; the stick one gives more protection and gets left behind everywhere. For mass giveaways, the three-section folding umbrella is the one that genuinely gets used.

One or two, done well. Marking all eight panels multiplies the cost and makes the result worse.