The first thing that I keep in mind while building a team for the spiral abyss is to have elemental resonance. I want to benefit from as many additional bonuses as possible. I cater to characters that can provide overall team bonuses like Sucrose. Taking an example of my C6 Sucrose, I can utilize her in any elemental reaction team or mono-elemental team except geo to deal a massive amount of damage. I use her with off-field damage dealers; Sucrose will shine in dealing area-wide damage. But she may fall off to deal damage to single enemies like Maguu Kenki. The second thing I do is see what kind of enemies I will be dealing with. Suppose there are enemies like Hilichurls that can be grouped in Sucrose's elemental burst. In that case, she can quickly clear out that floor and save the elemental bursts of other team members. I prefer not to overkill the use of elemental bursts and skills because I may need them in upcoming chambers for tankier enemies. Overall, I'll try to make your team according to the enemies you will face and keep investing in characters you have higher constellations on.