Use the following command to create a list not under version control files.
svn status | grep "^\?" | awk "{print \$2}" > ignoring.txt
Then edit the file to leave just the files you want actually to ignore. Then use this one to ignore the files listed in the file:
svn propset svn:ignore -F ignoring.txt .
Note the dot at the end of the line. It tells SVN that the property is being set on the current directory.
Delete the file:
rm ignoring.txt
Finally commit,
svn ci --message "ignoring some files"
You can then check which files are ignored via:
svn proplist -v