Sooner or later, you're gonna' be "in the pew."
(Do churches still have pews? Or have we just gone full-blown crazy and put movie theater seats in them now? I digress.)
Maybe you'll have a Sunday or two off and it will allow you to sit out among the congregants.
Maybe you'll take a sabbatical and you'll get to check out lots of churches.
Or maybe there'll be a time in your life where you're not actively leading worship but you'll still be in church.
How do you do that? How can you still use your gifting to support the folks up their leading without a microphone or instrument?
SHUT UP AND SING
First off, worship your guts out. If you've led before, you know what it's like to look at a room full of people who don't seem to care very much about what's happening, don't you? If you're in the pew, be the person who shows up early, stays late, sings, prays and stays focused during the worship time.
Don't try to figure out what's wrong with the band or make mental notes on what's wrong with the sound system. As much as you are able, turn that part of your brain off and support that worship leader by following his or her lead.
IF YOU GOTTA' TALK, BE AN ENCOURAGER
Once the worship leader finds out there's another one out there, they're likely to wanna' meet you. Take that opportunity to encourage them - mention parts of the service that went well or elements that obviously took a lot of work to pull off. Basically, say the stuff you wish people would say to you.
If that worship leader wants advice or constructive criticism, they'll ask. Don't waste their time with how you used to do it or point out failures on the platform.
BRAG ON THEM
Pull the pastor aside or send an email. Tell the leadership who you are and that you've been a worship leader. Then spend the rest of the time acknowledging the hard work of the worship leader. Don't tell the pastor all the stuff you would change or try to angle for a worship leading gig. Be concise and encouraging.
Somebody, somewhere once bragged on you. You probably never heard it or saw it, but it happened. Why not anonymously bless another worship leader with your praise? Pass it on!