I agree with the Pinterest suggestion . Pin loads of pics you like , don't think about it too much , just pin anything that appeals to you, even if it's completely unrelated to your own garden . Once you have about 100, search through them for themes .
Eg formal or informal planting styles, types of plants, colours, accessories
Personally like a strong structure with LOTS of dense planting , informal style , lots of texture and shape contrast in my planting , limited colour plalette , few accessories, low key hard hard landscaping .
But lots of people might find my style messy , not enough bright colours , not decorative enough, boring hard landscaping , not enough lawn etc .
HTH