make it dimmer and don't turn it on as much?
92 isn't bad...keep i mind that phones don't charge up to 100% and then stay there...they go up to around 99% and then drain a bit...when they reach a lower threshold (92% generally but it seems to vary by phone) it'll start charging again. depending on where in the cycle your phone was when you unplugged it, 92 might be acceptable.
i gave up trying to achieve awesome battery life using hacks and apps and stuff. Phones have this funny thing about them where using them drains the battery. Every app i tried crippled the phone in some way that i didn't like. I just bought 2 battery packs and about 6 chargers and put them all over the place at home and work. Now when i'm stationary for a any length of time I just plug in. I don't have to think about it and i can use the hell outa my phone with out being concerned about battery life.