It depends on the application...
I'll use a 234 if I'm making a lot of changes from G to C.
I'll use a 123 (and 1234) if I'm making changes from G to other chords.
1234 method
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| 1 | | | |
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2 | | | 3 4
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Other 1234 method I use makes it easy to switch to a D7 (see below)
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x | | | 1 1
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| | | 2 | |
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| 3 4 | | |
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Alternate D7 (a C7 slid up 2 frets)
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x | | | 1 x
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| | 2 | | |
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| 3 | 4 | |
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scosio