When we think we're all prepared to proclaim our assigned Sunday readings, are we sure? What about the Prayers of the Faithful we're also assigned? Don't the intercessions deserve ample preparation as well?
They're the bridge between the day's readings and their intentions. They bring the Liturgy of the Word to a close and better prepare us for the Liturgy of the Eucharist. They're the prayers that encourage us to think beyond ourselves and become more concerned with the needs of others.
The General Instruction of the Roman Missal #69 says that in offering these prayers to God for the salvation of all, we are exercising the office of our baptismal priesthood.
Think about that! What an honor to lead our fellow parishioners in the exercise of this office!
It would be wise to arrive at church an extra 10-15 minutes ahead of your normal arrival time and go off to a quiet spot to review the intercessions before the people start flowing in?
When we give these important prayers the attention they deserve, we can encourage our fellow parishioners to listen and respond more intently; likely resulting in greater outcomes for the people whom they're intended.
Also be prepared to read petitions you may not be comfortable with; those that are biased or slanted in some way, either politically or socially. It's another reason to arrive early and tell the sacristan or presider right way if you've got a problem with any of them so they can have another lector read them.
Better yet, if you know in advance that you'll be reading the petitions, ask your liturgist or priest a day or two ahead of Mass to see them as soon as they're written. You may not control what they say, but you can choose whether or not to read them.
The most unwise thing a lector can do is to change a petition's wording up at the ambo on the fly, especially if your pastor had his hand in crafting the petitions.
Have fun explaining yourself on that.