Catrin, short and steep is a lot of fun to ride. You get a lot of speed going down one side, pedal if you have to, then accelerate at the bottom of the next hill and don't start shifting down until the cadence starts to fall. If you get enough speed, even if the grade is 15-18%, you can reach the top and still not be in your lowest gears, and your speed might not drop below 12 mph. It takes practice and a positive attitude about how fun it all is. If the hill is about a half mile high, you can still make it half way or more to the top before the speed really starts to drop.
I consider myself a slow cyclist, not really slow, but I have enough ascents and headwinds in any given ride that I doubt if my speed will ever be significant, plus I can't get my average cadence to go over 75, and thus my average speed falls anywhere between 13.0 and 16.5, typically between 14 and 15.5. Last month I was out on a long solo ride, on roads I know well. I turned left off of one rural road onto another rural road and about 1/4 mile down was the glimmer of a male cyclist. Since I knew the road I knew there was a nice descent, followed by a sharp hill with a steep curve, and I thought, hmm, I bet I can take the cyclist on the hill. I gained on the male cyclist by picking up the cadence, then gearing up when I reached the descent, pedaled like mad, and I got the male cyclist about a 1/3 of the way up the hill, passed him at about 16 mph. His head turned to look at me when I passed him, he saw I was a female, and he shouted, "hey you are a girl!" and then he shouted after me "I am slow because I forgot to pump up my tires." Now that was fun. You see what he did wrong, he didn't accelerate down the descent, and when he got to the bottom of the descent he saw a steep hill in front of him and he downshifted at the bottom into his lowest gear, thereby dropping his speed immediately, and when I passed him he was going maybe 4 mph. When I crested the top I was still going 11-12 mph.
Short hills are fun. Long continuous climbs are painful. And of course it is not possible to accelerate at the bottom of every short hill but with increased cycling fitness those type of short steep hills are easy to do, just slower and in a lower gear.
One of the worse sounds to hear is a "swoosh swoosh" coming up fast behind you on a hill. That happens to me. I will be on a climb and being pleased with myself, thinking wow this is the fastest I've gone up this hill, and there is that swoosh swoosh sound and it is a male cyclist coming up fast behind me and then passing me on the hill going over 20 mph, and the male cyclist is invariably a senior with gray or white hair and probably over the age of 65. But then I am not skinny and I don't ride a titanium racing bike either.
Other people can probably contribute to the hill climbing techniques. Others might have an even faster and easier way to climb the short hills than I do.