Using graphite in the slots of the nut will help the strings slide better in the grooves. This help tremendously when bending or using the tremolo bar.
Stretch you strings after installing a new set. Tune it to pitch, then tug on each string, be careful don't tug too hard on the treble strings. What that does is, tightens up any slack that my occure when the string wraps around the tuner post. On a acoustic guitar, it does the same to the tuner post but also tightens any slack between the bridge plate, string pin and bridge.
If you de-tune your guitar a full step down or de-tune to any special tuning, use heavier gauge strings. A set of 12's or 13's will feel looser when de-tuned.
Always use a quality guitar cord!
Find out if your instrument is "active", meaning does it use a battery for pre-amp electronics. If your instrument sounds like your amp speaker is blown, or no sound, you battery is weak. Always put in a new battery before every gig!
If you guitar is acting up, try a good/different guitar cord. Try a different amp. By-pass your pedals in your chain. After you have eliminated all external components, and your guitar is still acting up, now you know it's your guitar not you gear.