Many accessories can be homemade for a modest scale planting, but that becomes impractical at some point, and our physical guards against weeds, rabbit, and deer, along with fertilisers, herbi/fungicides and other pest control are made for the task and ready for delivery to your door. If you live in the city where there are no roaming herbivores, with good garden soil and high shelter from wind, you often need no accessories at all, except Rootgrow fungi, which is great on perennials and bulbs.
Rabbits and deer:
Both of these animals will do a lot of damage in one night to young trees and hedges. They are more systematic in the lean months, but still seek out your tender young plants among the lush grass all summer. You might only see them rarely, but if they are in the area, you should make or buy protection to keep them from decimating juicy young trees. Many species that are considered "deer resistant" will still have their spring buds snacked on.
There are three good options for protecting all the branches of valuable orchard and ornamental trees: physically fencing the entire area with wire or plastic to about 12' / 4m, or giving each tree a custom guard (which could become a permanent enclosure: deer don't like to jump into confined spaces, so these can be under 4m tall), or using a full time alarm dog.
With other, less precious trees, it is enough to save their trunks from being chewed with 60 - 120cm tall cheap plastic guards, or 80-120cm tall strong strimmer proof plastic guards), or a disposable, expanding plastic spiral for sapling trees and shrubs, which protect against rabbits too.
Don't be the grower who says "I'll ring off my new hedge with string and clangy metal to scare the wild animals off", or who expects a homemade brew of smelly things to deter deer, or a chilled out dog who sleeps in the house. Strong chemical deer repellents cost money to re-apply (and some of the best ones smell terrible from a distance), gadgets with lights lose their effectiveness on the same deer over time, and some deer are bold anyway because they are more used to humans. All deer are boldest in winter when hungry, so these set-ups may work for a while, until the animals get hungry enough. If you make your own plastic guards from scrap material, design them with appropriate ventilation and translucency, and check them as your plants grow for restriction and rubbing.