Don't evangelize. Evangelism is marketing.
Use clearly-defined logic to convince peers of what works and what doesn't.
Don't cite "best practices"; they're dogmatic. What works for "popular" developers isn't going to always work for you. Instead, clearly lay out why technique X is more likely to work than technique Y.
Here's an example I'll throw your way:
Consider you're on a small team of ideologically-divided programmers. Your task is to unify them and build a client-side tool—let's say a calendar.
Let "Adam" be a developer who favors a one-size-fits-all solution: ExtJS;
Let "Bill" be a developer who favors a "toolkit" solution: MooTools;
Let "Cam" be a developer who favors a dogmatic "best practices" solution: jQuery;
Your "enlightened" perspective is that building from scratch is the best solution. How do you convince your team that you're "enlightened"?
Suppose you make a pros/cons list for each position. It might look like this:
Pros: Familiarity, cleaner
Cons: Takes longer to produce, requires effort
Weighing the pros and cons, it's clear that Bill (MooTools) and you (hand-written) have the most flexible solutions.
From there, ensure your team is educated on how both strategies work. Heavily research the topic in order to more efficiently write "homegrown" code.
If time or complexity become an issue, consider deferring some responsibility to the "toolkit": it's likely to have an API for your problem.
Don't underestimate the power of "one-off" hand-written code. It may not be unified under a shiny namespace with slick marketing behind it, but it can still get the job done.
Above all, you need to educate your clientèle (team). Help them to understand why your position is going to work better. If you do your homework, people will benefit from your knowledge. Remain open-minded: if someone else raises a good point, compliment them on it and then research it further. Perhaps you've overlooked something.
If you want to be compelling, you need to fervently study the topic. You need to be the expert. Otherwise, you're driving with some form of blindness and will experience turbulence.