Dolphin is very nicely setup so that most of the default settings are set to be the fastest Dolphin can run and changing the settings will only cause more demands on the system and slow you down (and fix broken things in some game). The games that need special settings generally have those set in their Game INIs (I am not sure if all the games are set but the ones I own all have the right settings with just me transferring the iso from my disc to my computer, so far)
The exception to the rule is the Graphics backend and that will vary depending on the game you want to play and the GPU your system uses. Also all the settings here have nice explanations of what they do and their possible impact on performance (a very nice touch).
My only complaint would be having lived through the era of emulators you needed to change all the settings per game to get it to run well, if at all, that Dolphin takes away some of the fun of emulation by being too well designed (making tweaking less useful and necessary).
The exception to the rule is the Graphics backend and that will vary depending on the game you want to play and the GPU your system uses. Also all the settings here have nice explanations of what they do and their possible impact on performance (a very nice touch).
My only complaint would be having lived through the era of emulators you needed to change all the settings per game to get it to run well, if at all, that Dolphin takes away some of the fun of emulation by being too well designed (making tweaking less useful and necessary).