I'd link to the forum post I recently posted in the RAMPS sub-forum about 24 Operation (look for a thread called 24V with Ramps 1.4 questions), as the forum thinks that this post is spam when I try.
And yes, I prefer either M205 or car automotive blade fuses. They're common enough and do the job. The blade fuses make particular sense as they're easier and easier to get hold of, and 15A is a fairly common value (which is good for a 12V PCB heated bed - as they tend to vary in current from 10A to about 13A due to track width tolerances). Another advantage is that you can remove the fuse and connect an Ammeter in place of the fuse (at least, as long as your multimeter can support the current). Provides a good diagnostic tool.
Other things are:
Connectors: Due to RAMPS cramped design, the connectors are all over the board, instead of purely at the edges. This is particularly true of the stepper motor connectors. Also, they're not locking type connectors, and no provision was made so you could use any sort of locking connector on the PCB (mainly by adding extra space around the connectors - which there isn't room for as the designed is cramped. Another example is the D8 and power connectors being too close, which means you can't use the Phoenix-style screw connectors used on the power on the D8/9/10 connectors as well, without chopping a piece out of one of the connectors.
Voltage inputs: As per RAMBo, it makes sense to have 3 voltage inputs. One that supplies the Heated Bed output, one that supplies all the other MOSFET outputs (eg: fans & nozzle), and one that supplies all the Motor driver boards. This way, you can run 12V on your hot end/fans and 24V on your motors and heated bed easily, or even have different PSU's for all 3.
Hope this helps.
And yes, I prefer either M205 or car automotive blade fuses. They're common enough and do the job. The blade fuses make particular sense as they're easier and easier to get hold of, and 15A is a fairly common value (which is good for a 12V PCB heated bed - as they tend to vary in current from 10A to about 13A due to track width tolerances). Another advantage is that you can remove the fuse and connect an Ammeter in place of the fuse (at least, as long as your multimeter can support the current). Provides a good diagnostic tool.
Other things are:
Connectors: Due to RAMPS cramped design, the connectors are all over the board, instead of purely at the edges. This is particularly true of the stepper motor connectors. Also, they're not locking type connectors, and no provision was made so you could use any sort of locking connector on the PCB (mainly by adding extra space around the connectors - which there isn't room for as the designed is cramped. Another example is the D8 and power connectors being too close, which means you can't use the Phoenix-style screw connectors used on the power on the D8/9/10 connectors as well, without chopping a piece out of one of the connectors.
Voltage inputs: As per RAMBo, it makes sense to have 3 voltage inputs. One that supplies the Heated Bed output, one that supplies all the other MOSFET outputs (eg: fans & nozzle), and one that supplies all the Motor driver boards. This way, you can run 12V on your hot end/fans and 24V on your motors and heated bed easily, or even have different PSU's for all 3.
Hope this helps.