Spoiler for those who don't want to read the whole thread: Cusp signs are not valid. However, the mixed energies you are feeling are.
Now, before I invalidate cusp signs... what are cusp signs? Cusp signs are labels used to designate the mixture of neighboring sign energies. Most of the time, I see this being used for Sun signs. For example, you could be a Pisces-Aries cusp, a Taurus-Gemini cusp, etc.
The problem with cusp signs is that it fundamentally works against the workings of astrology. Let me ask you a question: Can a planet be in two places at the same time? If you support cusp signs, you would say yes to this question. Of course, this is not possible.
In astrology, the location of a planet is determined by degrees. If you look over to the Sun glyph, the Sun is currently at 1 degrees Aries. If you play around on Planet Watcher, you will soon realize that the planets can only be in location, and therefore, one SIGN at a time.
If you want to play around on Planet Watcher to see what I'm talking about, here's the link: http://planetwatcher.com This is also a GREAT site to look at when it comes to transits by the way. You really get to see how all the planets over time and it's great.
The only time it would be possible for cusp signs to be possible is if we had two planets to designate the space. So if we wanted to make the Gemini-Cancer cusp true, we would need to have one Sun for Gemini, and one for Cancer... We don't have two Suns.
So, if you're wondering where and how to label the neighboring energies you have, check the following: 1. Your Mercury and Venus. Chances are, they're in neighboring signs to your Sun. 2. Check if your Sun's at 29 degrees.
1. With Mercury and Venus being in neighboring signs, it shows that there IS a mix! The mix is just labelled differently and appropriately.
2. If your Sun's at 29 degrees, it's at the anaretic degree. The overlap between signs isn't strict, meaning that there CAN be a blend of energies. Do note though that your Sun would STILL only be in one sign though.