If you want to seduce a girl, you have to be smart enough and should have knowledge about that girls. Like what does she likes to do, what does she likes to talk? etc.
Unlike other girls, German girls are well educated. If you talk to them about politics, weather, money, food. It would be a worthless try. You can talk about technology, science because they like man with intellectual level more than them. So prepare yourself and do some home work about that girl. Don't be shy about talking Donald Trump, Angela Merkel or about your iPhone. May be you would not get positive response at the first day, but don't get frustrated.
As you know half of German people are not settled, but girls like settled man. If you have some business, talk about it. Let them know what you do for living. Do not argue with her for a silly matter. If she loves something, which you don't like, respect her choice.
Learn some German word to flirt her by her own language. Do not talk about any offensive matter. Take good care of her. They also get bored quickly, use some jokes to make them laugh. If you get a feeling that she also likes you. Say the magic word.
