Both these Bet Types are demonstrated on the downloadable spreadsheet containing "The Faithful 5" details, as the matches to bet on for "The Trusty 2" should be your 2 Bankers as used for "The Faithful 5" and then, in the case of "The Thrifty 3", your next strongest prediction.
Again, they both use either the Draw or the Away as the fallback position. For "The Trusty 2" this extends to both Bankers, but for "The Thrifty 3" it applies only to the second Banker. This gives four betting lines for "The Thrifty 3" and three lines for "The Trusty 2".
We have already mentioned under the section entitled "The Fab 4 / The Smooth 4 Bets" how it must be checked with all hedge bets that the return(s) from the most likely winning line(s) will cover the stake. If not, the number of hedge bets must be cut back until that requirement is satisfied. With these 2 Bet Types, however, and unlike "The Fab 4", we proportionally place the stake amongst the separate lines so that this will not be a problem. This can be clearly seen on the spreadsheet.
Statistically you ought to find it easier to win with these Bet Types than with any of their quintuple or quadruple equivalents, but your returns will be very much lower per win. Don't expect to get a lot back from these forms of betting therefore, although if you do it sensibly you should find that you stand a far better chance of coming out on top overall.