I think any work with fluency is going to improve wcpm. I would start by modeling fluent reading to your students. They need to hear and understand what fluency sounds like. Definitely repeated reading as the other poster suggested. You could incorporate echo reading and choral reading as well.
Fluent readers need the ability to quickly and automatically decode words. That can be the first break down of many possibilities. However, if this isn't in place, there is a high probability that fluent reading will not come unless the student is only provided words that the student has memorized by sight. I know some schools push this above all else, but any unfamiliar word then impacts fluency.
Some fluency programs have a reader for the student to read along with. Read Naturally is one of them. What this program can do that you may not be able to do as a teacher is read what is at the individual student's level. You may have a student reading at a 1st grade level needing fluency work and one at a 3rd grade level needing fluency work. The student that is below grade level will benifit least by choral or echo reading on passages that are above his reading level. At that point the student will just be learning to speak with cadance and speed, not read with fluency because there is no way the student can read what is two grade levels above his reading level with any sort of accuracy. Sure he might end up memorizing a few words, but significant improvement will not be gained by whole class choral reading with diverse levels of reading ability.
Fluent readers need to really understand the words that create phrases. They not only need to be able to read them they need to be able to know what they mean. It allows them to comprehend as they read and know how to stress and phrase portions of the sentence.
Finally, improving fluency must also include comprehension. A fast reader isn't necessarily a fluent reader if the reader doesn't comprehend. Fluency includes reading passages at both the level where a student can decode accurately AND comprehend what is written.
Another option would (if you have a computer available to you) would be to record the student so they get the instant feedback of how they sound when they are reading.
One website I have used is PodoMatic.com, it's a free site that you can record "podcasts" with. There is also a timer when recording so the students are able to judge their rate independently. They you could go into the other areas, such as phrasing, pausing, and intonation.
Amazing website with links to tons of interventions. Just search for fluency then second grade. Others are right in that fluency with connected text is a composite skill made of up different subskills, so to the extent that a child struggles with accuracy or fluency with any of those subskills, such as fluency with phoneme blending, the student will also struggle with overall fluency with connected text (reading passages). But, fluency with connected text isn't just a collection of various other skills, but a skill itself, and there are activities below which address that to:
Fluency is not only reading with automaticity, but also reading for meaning with expression. If students are relatively comfortable with decoding, you can move on to expression. I use a text that is at my students' independent level (not instructional level for this), and have them choral read in a monotone "robot" voice. Then I have them COMPLETELY overdo it, and be a total ham. Arm gestures, loudness, over-the-top theatrics, you name it. When we get to individuals trying it, it's often not as over the top, but it is in the range of appropriate expression. Obviously when we do it in class like this, the expression is contrived and copied from mine, but as the year progresses, I've noticed my students incorporating this into their own reading. It's a process that takes time, but is well worth the investment. Plus, the kids LOVE being allowed to overdo it and act silly in class.