For me flavors with vanilla notes and caramel/nutty notes are the only ones I can vape for very long without switching. I have been doing the whole DIY juice thing and after about 3 weeks I finally made some stuff about a week ago that I haven't been able to stop vaping YET!! First flavor ever that I have vaped for an entire week straight. Only flavor I have ever even vaped a full day on without stopping. I usually love switching up my juices, and I have sooo many right now but I have been steadily vaping this new batch and I have about 60 ML steeping!! I have also noticed recently how effective steeping really is. When I order my favorite 555 blend it is made to order and extremely fresh when it gets to me. I don't really enjoy the taste at first at all. After a week though!!! OMG NIGHT AND DAY! It is amazing how it brings out the nutty notes and makes the juice more smooth and Gives it less of a "bite" (don't know how else to describe it). Sorry for the rambling, I kinda got off track, but the point is...For me, a liquid has to have at least a tiny bit of tobacco like flavor, cannot be too sweet, needs to steeped, and needs vanilla, caramel, or some nutty notes to be an "ALL DAY".