Forum Story Structure and Transitions

I'm writing a story about two friends and their childhood. The present day story takes place the day before the narrator is due to sing at a friend's funeral and as he thinks about the friend he has loss, he recaps on his childhood. Most of the story is a flashback showing him and his friend growing up, naming the things the narrator remembers most. I want to switch back to present day some times throughout the story until the very end when the narrator is seen at his friend's funeral paying a tribute. As of now I have a chapter of present day after each memory of the narrator's past. But this seems too hard to do.

What is a better way to switch between the present and the past without making it so complicated on me and the readers' part?

Thanks...

Sorry if this question isn't clear!