really, you walk down to a song that speaks to you, or that really makes you feel kadosh and spiritual, and helps enhance the importance of the moment, according to you. personally, some songs i would choose would be:
meheira- shwekey
bo’ee beshalom- shwekey (libi b’mizrach)
birkas habayis- (dunno original, but its on last track of baruch levine’s chassan torah. its the middle song)
ma ashiv- baruch levine (hashkifa)
then there is one song that i don’t quite remember the name, but its on shloime dachs’ dance all night as one of the chuppa songs (no music, just sax)
these are just some, among others i would choose. these are the ones that stand out most to me.