Dear Ernst,
when searching for an Muhurta and I have to choose between a bad Tithi or an bad Naksatra, I am thinking that the better choice is taking the bad Tithi because, as far as I understand you properly in your book, Tithi determines how one feels about the event and Naksatra determines what developes or grows out of the event. If I understand you correctly then I am thinking its better one feels not so good about, for example, an wedding, and then the marriage developes in something nice rather then one feels good about the wedding and then the marriage develops into something bad. Do you understand what I mean? Do you agree with that? Is it under such circumstances better to choose a good Naksatra over an good Tithi?
Ps.: Sorry I have not replied to your last answers. I was so busy. I read it and thought about it. I will reply there later.
...and what would you say for an wedding Muhurt if the Tithis is Ekadasi or Dvadasi Krsna Paksa and the Naksatar is Magha and there is as Siddha VT Yoga and a Amrita VN Yoga?
I would choose the good nakshatra, but try to get a vtn yoga that includes the bad tithi which makes the tithi work well.