Data Matching
I find that it helps if you create match keys on common elements if you are looking at matching / merging data during data migration.
For example if you are matching post codes you may want to normalise all postcodes into the same foramt e.g. remove all spaces prior to doing any matching.
For addresses it may be worth creating a string match key from the address but here you have to be caregul since if you strip unwanted characters like '-' out of house numbers 1-11 becomes the same as 111. In particular this is important if you are using any fuzzy transforms in SSIS