I am not an expert with Persona Q but I did spend over 150 hours playing the game. During that time I learned a few things that could be useful to others playing the game. We recently had a dude write into the podcast asking for some tips and I figured I might as well share them with everybody else.
Here is a fusion chart made by Silentsword. The chart contains all the instructions on fusing.
This link will take you to a list of Personas as well as the skills they can learn. You can use this with the fusion chart to fuse any persona you want.
This link will take you to a list of skills and descriptions on what they do. Look over these and see which skills match how you want to play.
This one will take you to a list of skill cards. You unlock skill card extraction partway through the third floor of the third dungeon. Once you get there, you can start giving skills to sub-personas and really strengthen your team.
Here is a link to a FAQ I referenced several times during my time with the game. Hopefully it will help answer any questions you might have.
At some point you can use the navigator skills that will let you gather from power spots safely, as well as skills that raise the power spot drop rates. This will allow you to really earn money fast. With more money you can summon more Personas, sacrifice them, fuse them, etc. At that point you can make your team nearly anything you want. I copied the information from the above links into a spreadsheet so I could manage the data better. These were the spreadsheets I talked about on the podcast if anyone was curious.
Two things influence the Personas I choose: their HP/SP boost, and their skills. If you look at your sub-Personas, they each have boosts that get stacked on top of the users HP and SP gauge. You’ve will notice different colors in the character’s gauges; it took me a while to figure out what that was all about. The smaller, different color sections are the boost provided by the sub-Persona. The awesome part of the SP boost is that your character will get that much SP back after a fight. So if you use your SP wisely (not use more than your sub-Persona bestows) then you can stay in the dungeons longer. The same holds true for the HP boost as well. Also worth noting, these numbers increase as the sub-Persona’s level does as well. They go up by one or two each level. Don’t worry if the numbers don’t go up with some levels, this is normal and the stats will likely increase for the next level. Keep in mind, if the sub-Persona is five or more levels below the character controlling it, you will receive penalties on attacks performed by that Persona. The penalty increases up to a point. Long story short, keep your sub-Persona and characters at similar levels. If you want more details on this, check the frequently asked questions section of the FAQ I linked to earlier.
As for skills, I built my main party around covering all the elements; agi, bufu, hama, etc. Each character was my go to for specific skills as well as a backup for other skills. For example, I focused Yukiko on fire and healing, while she was the backup caster for wind and almighty. Thus, depending on what skill I wanted the character to cover, I would select a sub-Persona to match. This becomes less of an influence once you unlock skill card extraction as you can just give your sub-Personas the skills you want.
My main team was Makoto (P3MC), Mitsuru, Yu (P4MC), Yukiko and Naoto. Naoto was my main caster for light, dark and almighty. From her stats (plus the rings I gave her to boost them), she would often act first and destroy all enemies before anyone else could act. I eventually started called her “The Hammer” since she was so powerful. Also, I would recommend using Fuuka as your battle navigator as her healing abilities were more useful to me than Rise’s turn abilities.
Have fun playing!