If you have siblings you've probably realized by now that you don't see eye to eye on everything. In fact, you can attend the same events and walk away with completely different experiences. Different points of view can be a real boon to capturing your family memories.
When I was a kid, my brothers and I took a family vacation to Jamaica with our Mom. I had so much fun going to the beach and to restaurants. I also remember being haunted by the poverty. My oldest brother, on the other hand, was bored. He spent most of his week reading under a palm tree. If we were to share recollections of that event now we would very likely have completely different memories.
Sometime when you have a to chance to visit with your siblings - even if it has to be on the phone - ask them to recall a specific event. Perhaps Christmas at Aunt Betty's house when you were kids. Ask them how they remember that experience.
Ideally, afterward, you would encourage them to write down their version of the event. If they protest, write down to the best of your ability, a recap of the conversation. When you finish writing send them a copy.
One of the best ways to get people writing is to start the writing process for them. You'll find that when they receive your document they will want to edit or re-write it. All the better for ensuring you capture their point of view.
Difficult situations from the past can also be handled this way. If your parents were divorced when you were young, you and siblings may remember it differently. Ask your siblings to recall or write about their memory of that time in your lives. Not only will it show you had different experiences it may just provide a healing experience as well.
The more siblings you have the more varied the memories of your event or situation will be. Contact your siblings soon and start capturing the events of your own childhood.