Take the number thirteen , various reasons for this one being that there were thirteen people at the the last supper and the thirteenth person was either Jesus (who got crucified) or Judas (who betrayed Jesus) , but surely all the others could have been the thirteenth person , then what about the people serving etcetera.
Also you get thirteen loaves or cakes in a bakers dozen , in case one is not up to standard. Most of the time all thirteen will be up to standard so in this case thirteen is a very lucky number.
Then there's don't walk under ladders , well that's surely rooted in common sense as ladders aren't exactly stable and if someone's up there they could drop something on you , got that from an argument between Batman and Robin in the sixties TV series where Robin comes up with various superstitions and Batman explains how they may actually have some foundation.
Then there the magpie rhyme , lets face if you see a single magpie , anything that happens like missing a bus , or the lights changing to red could be interpreted as sorrow , similar to horoscopes. Incidentally , apparently astrolgy apps are very big on smart phones , although that's not surprising given the sort of people I've seen with smartphones. Anyway I've now done fourteen posts this year so it won't bother me til this time next year.