It is not that typical for locals to send flowers of their own choice, but if you wish, you can send or bring them to the _home address_ of the family of the deceased for them to keep it there.However, a funeral is a busy day and locals prefer to keep everything organized at the ceremonial hall. You can try contacting the family or employee of the deceased to see if you have the option of paying for a "hanawa" of their arrangement. These are hanawa.
http://images.google.co.jp/images?hl=ja&rls=com.microso...
Typically, in an important person's funeral, many hanawa will be exhibited, and there will be a name on each one showing who presented it. If you are an important person yourself, they might appreciate putting your name on one of these just to show what great relationships the deceased had enjoyed.
Otherwise, typical ways of showing grief without attending the funeral is the telegram. If you live in Japan, NTT has certain forms appropriate for funerals, but if you are overseas, any simple design and any sentence would do. They would often be read out loud during the funeral.
If you are attending the funeral, you still can send a hanawa but not the telegram. You bring money, as mentioned, in an appropriate envelope sold at stationary shops.
I've never seen anyone sending/bringing flowers by themselves to a ceremonial hall in Japan.
