@biggreenapple24 don’t we all 😂
@Nottodaythankyou123 , the reality is that herbaceous perennial borders take time and work to get right. Unless you’re prepared to pay a lot of money for mature plants and shrubs, and to buy a lot of them, you have to accept that it will take years for them to grow and form a planting mass.
The way I go about it is to do it in stages, starting with the structure - ie trees and shrubs - in the first year. Some shrubs grow very vigorously. Even a small fatsia japonica will grow to five or six foot tall in one season, and the evergreen leaves are beautiful. If you plant 3 of them at intervals in your border, you will enjoy them growing all spring and summer long. I would do the same with hydrangeas, skimmias, pachysandra, sambucus nigra black lace and daphnes - all these shrubs are happy in shade (or part shade) and are not fussy about soil. They will give you lots of different foliage colours and shapes to make your future perennial flowers pop. Plant the ones that grow tall (fatsia, sambucus), at the back, and the ones that are more petite (skimmia, pachysandra) towards the front.
If possible, try and buy shrubs that are larger than the smallest, 9cm pots, or you may have a shock when you get delivered a box of twiglets 😮.
You may also want to add some Japanese maples (acer palmatum), as a lot of them don’t like too much sun.
B&Q often have a good stock of good sized trees and shrubs at reasonable prices.
I would also add some ferns, because I love them - they’re not expensive and look dreamy in a shady border.
Then you can sit back and admire your work - your work is done for the year. Anything else you decide to plant this year is icing on the cake. Maybe buy a few packs of impatiens or begonias and fill some gaps - they both do well in the shade.
Now you have a year to leaf through catalogues and watch YouTube and decide what perennial flowers you want to plant next year.
Remember also that planting is rarely permanent. Obviously you’re not going to want to move mature oak trees, but gardeners are always moving things around in their gardens - if something isn’t right in its location, dig it up and move it somewhere else (or offer it to neighbours). So you don’t need to worry about making mistakes - it’s all part of the process.
The only thing I would avoid is any plants that are susceptible to slugs and snails, like hostas. It’s a bit heartbreaking when a plant gets razed to the ground.