For backing up the System (OS and programs), imaging with
Macrium Reflect Free can't be beat (unless you get the paid version of Macrium Reflect but, for most people, the free version is fine).
However, for backing up data files and folders, a folder/file syncing program, such as
FreeFileSync, is much more efficient. When set to Mirror mode, it will compare your data drive, partition, or folders to your backup drive, then copy new and changed files on your data drive, partition, or folders to the backup drive and delete files on the backup drive that have been deleted form the data drive, partition, or folders. FreeFileSync also has the option to send deleted files to a versioning folder or drive. That will help protect you from data loss due to accidental deletion and allow you to recover earlier versions of files.
When using imaging and folder/file syncing, it is best to segregate your data files from your System files by having them on separate drives or partitions.