Think about how you currently use outdoor space as well as what you want to be able to do
Think about what areas are sunny/shady, especially if you plant trees think about where the shade from the mature tree will fall
How much ongoing maintenances you want to do, if very little think raised beds / pots for plants, add bulbs / ever green plants, ones that don't need trimming every year.
Climbing flowering plants make a fence look nice without the work a hedge takes, if you want a hedge you don't need to use conifers, my neighbour has one using forsythias which gives lovely spring colour.
Do you cook? If so do you want a herb garden / space to grow veg?
Do you want a greenhouse? Where will you store garden tools/bikes/ outdoor furniture in winter (or have something that can be left outside all year)
Lawns take work, look at other options if this doesn't appeal, clover lawns or wildflower meadows can look pretty but don't need mowed every week
Do you have kids? Where can you store outdoor toys? (A small 6/4 shed in a corner can double as playhouse and toy storage)
Do you have pets that need outdoor space?
Do you want space to hang washing? Where can you put it to get max benefit from sun/wind but reduce how obtrusive it is?