There is no way to tell you what is the best because it varies by the situation. Certainly backing up daily and having transaction log backups are good. The decision comes down to, "How much data are you able to lose?". If 3 hours is good then you are all set, if not, then you need to increase transaction log frequency and might want to add differential backups during the day to reduce the # of steps required for a restore.

One other thing you don't mention is where are your backups going to? Are they on a different drive than the log and database files?