For basic spheres you can use ordinary hedge shears. You don't need secateurs.

i like felco for hand pruning .... what flora call secateurs ....

https://duckduckgo.com/?q=felco+pruners&t=ffcm&iax=images&ia=images

like any tool ... you get a better tool.. by paying for such .. i like these because they can be taken apart and cleaned and sharpened ... mine are about 30 years old ... and in those years... if i had bought cheap ones every year.. well.. these paid for themselves many times over ....

hedge shears ... whatever ... i just got rid of all the plants i had to shear once or twice per year.. lol ... just go to bigbox.. and find a pair that is in your weight category ... and you like the feel of.. etc ... whatever feels comfortable ...

ken

For topiary secateurs are not the best tool because you want to cut a whole smooth surface not invdividual stems. It's shearing rather than pruning. You can get special topiary shears which look like old fashioned sheep shears. I have several box balls and I just use my hedge shears.

Thanks so much for your advice. I already have those Felco secateuers, but I was looking for a recommendation for a brand of hedge shears. Does Felco make good hedge shears too?

Yes. But there are many good brands.