I don't claim to have all the answers but there are a few "DO's" and "DONT'S" I've learned over the years which have helped me in setting up, transitioning and closing corporate worship times.
Study the lyrics of the songs you'll be leading in advance.
As you read/sing/pray through the lyrics during preparation, ask God to show you a verse or a short illustration that you can use which will allow the lyrics to evoke a deeper personal response as people are singing them. What you say should just be an extension of what God is showing you in your daily spiritual walk.
Begin corporate worship with a definition of worship.
Understand that your corporate worship gathering will most likely consist of a few non-believers and/or young believers...those who may not understand why we stand and sing together. Providing a definition of what worship is and how your church expresses it (singing, clapping, raising hands) helps them understand what is going on around them.
Direct verbal transitions toward God, not people.
Most worship songs are prayers set to a melody. Allow your speaking to be an extension of the song, not a pep rally cheer. The congregation is much more likely to engage when the worship leader is modeling worship, not demanding or coercing it. Your transition prayer doesn't have to be super eloquent and should not be very long. Perhaps it's just thanking God for a truth about Himself that He revealed to you during your preparation or even while you were leading the song. If possible, write it out ahead of time and memorize it if you have to. Eventually, it will flow naturally.
Encourage members of your worship team to share during corporate worship.
I know in larger churches it can be difficult for people in the congregation to really get to know the people on your worship team. The less people know you, the harder it is for them to trust and follow your leadership. I encourage our team to listen to the lyrics during their weekly preparation and then I challenge them at rehearsal to share what God revealed to them. Sometimes, if I believe what they share is what our church needs to hear, I'll have them share it during worship. I give them a time limit and help them frame what they're going to say. This allows the congregation to see the non-performance side of our worship team while building trust with the congregation.
Go longer than 90 seconds.
After that, people tune out and don't care about what you have to say anymore. Going longer can be an irritant to your pastor as well. You don't want to cut into his teaching time or steal his thunder.
Point out how the congregation is NOT demonstrating the desired response.
Putting the congregation on a guilt trip is the biggest worship killer out there. Instead, give people permission to express their worship as God leads. Growing up in a conservative Baptist church, the only biblical expression I saw was singing. If people understand there are other expressions described in Scripture and that it's OK, more people will begin to demonstrate the response we're looking for.
Don't use corporate worship as a time to give a mini-sermon on how the congregation should be worshiping. Either ask your pastor to do that or see if he'll allow you to speak on a given Sunday.
Make your prayers and illustrations inentional and different from the lyrics that are sung. Never lead into a phrase by quoting it before it's sung or by repeating a line you've just sung. This also applies to ending every song with "amen" or some other cliche phrase. Be aware of bad habits that have crept into your worship leading.
I hope this helps. I know that putting these things into practice have really helped me become a better worship leader.
I'd be interested in hearing what you've done to help your speaking/transitioning during corporate worship.