Losing a loved one is one of the most horrendous events a person can go through. It leaves you feeling mortified, helpless, and ultimately... speechless. It's very difficult to find the "right words" to say during these times and truthfully, I don't believe any right words exist. If you lost a loved one, or you know someone who has, a good starting point is to look for scriptures, writings, or poems that can help convey the situation and emotions being experienced.
In the beginning, when I want to post an entry about my brother, I found my mind going blank. I would sit in front of an empty text box for numerous minutes with nothing but a blinking cursor staring back at me. The reason it would start this way, time and time again, was because I had no starting point. I knew how I felt and I could see the images of the various memories I had in my head, but I simply couldn't express it outside of my heart and jumbled mind.
I did some quick searches online to see how to overcome this, but didn't get anything extremely useful. There were plenty of resources to tell me how to overcome the typical "writer's block" such as distracting yourself for a few minutes or perform some kind of meditation. These may be great methods if you're looking to clear your mind of the topic for a little while, but after losing a loved one, it cannot be helped that you'll be thinking of that person for hours on end. In fact, you almost have this unhealthy desire to think and express the way you feel about the person. And guess what? One of the best ways to relieve this is by writing it down, so simply walking away won't cut it.
One search I performed finally took me to a great source of how to start writing my thoughts and feeling. I decided to read some entries within the book, "Do Not Stand at My Grave and Weep". This book contains a surprisingly well compiled collection of scriptures, writings, and poems on the topic of losing a loved one. Reading an entry just before I start to write my journal entries and memories of my brother has helped me tremendously. Reading excerpts from this book has even provided me with some sense of solace.