There used to be time when Super Bowl winning teams had a good chance to repeat the feat the following season. The last time there was a repeating champion was for Super Bowl XXXVIII and XXXIX titles - the New England Patriots continued to dominate the NFL, winning three championships during four seasons.
Teams have come close to re-visiting the title game but for one reason or another, do not managed to win the game; the Buffalo Bills had an emotionally-draining four losing-appearances in a row (from Super Bowl XXV, XXVI, XXVII and XXVIII).
For the teams that do retain the championship, there are keys to making the play-offs, getting to and winning the Super Bowl title all-over again.
Play as a team, win as a team.
Finding the right chemistry within a team is crucial, all aspects of offense, defense and special teams need to believe in the philosophy of the coaching staff and the plays they want run. After winning a Super Bowl, it can be more difficult for a team to maintain the same quality-threshold as before - some players see it as an opportunity to cash-in on the championship status and move on to a bigger contract elsewhere.
If the organisation can keep the core of the team together for as long as possible, the greater the chance of success; experience as to what it takes to be a winner (having already done it) can sometimes be preferential over sheer physical ability.
If it ain’t broke.
The NFL game does evolve at a fast rate; find something that works and 10 other teams will adopt something similar (the wildcat offense got the league buzzing recently). Having a system or style which won a title in the previous year, shouldn’t be dumped in favour of something experimental, unless last season’s Super Bowl winning schemes are less-effective in the new season. A team should keep playing the same as they always have after a title win.
St. Louis won Super Bowl XXXIV on the strength of a superior passing-attack; they never gave up on it, even though they failed to repeat (going back to Super Bowl XXXVI two years later) it was a scheme where few teams could handle it on a regular basis.
May fortune smile on you.
With all the best preparations, a talented coaching staff, roster of players, schemes and play-calls; nothing is ever guaranteed. What happened during the glory of a Super Bowl season could be the complete opposite in the next season: serious injuries, a blown coverage, a costly flag on a play, a fumble, interception or miscue when it is least expected.
These are just a number of variables which can derail any attempt on the chance to repeat as NFL champions. If it were easy then many teams would do it often, only a select few players have ever won the Super Bowl, let alone repeated as champions. In the end, all any franchise, coaching staff and players can really do is hope it all works out the right way again.