I don't have any misc/other/etc categories for actual purchases - I do have a general "firefighting" or mini emergency fund which I try to keep topped up and use to cover unexpected, urgent expenses which aren't covered by another category.
What can be good practice for this, although it's probably a bit more of an advanced technique (better for after you've got the hang of the basics, maybe) is that when you make a big "one off" purchase, ask yourself is it really a one off, when might I need or want to buy this thing (or something like it) again? Even if the next instance is likely to be years in the future, you can roughly calculate e.g. appliances should last about 8-12 years, phones last about 3-4 years, computers 6-8 years, a fridge lasts 20-25, and then you just take whatever the purchase price of a new model would be now, plus about 10%, and put it in as a goal on the category with a date of roughly when you might need to spend out that amount.
I don't do one category for each appliance, but I know for example we've just replaced the 9yo washing machine, and I bought the tumble dryer 2 years ago and our dishwasher is over 10 years old and limping on, so when we replaced the washing machine, I took the dishwasher replacement fund, which was mostly full, and was able to almost completely cover it. I've started a new dishwasher replacement fund and sort of fingers crossed dated it for a year's time hoping it hangs on that long. When we do replace the dishwasher, I'll probably rename it from "Appliance replacement (Dishwasher 2025)" to "Appliance replacement (Robot vacuum 2028)" and stick whatever budget we want to have available to upgrade when the date comes round, because none of the big appliances are likely to need replacing this decade (touch wood!). We do the same for phones and computers - rotating which of us is due a replacement, one electronics category.
As it gets closer to the expected replacement date you can also adjust the date and/or target amount based on inflation, any specific model you have your eye on, how well the current one seems to be running, how your finances are doing etc.
Then for smaller things like if I just needed to buy a new saucepan or tape measure or printer paper or something - I have a "Household items" category. I put any boring-but-necessary spending in here and that allows me to see what my average spend is, so once we got far enough ahead with other expenses I just fund it upfront which means that there is usually some money in this category to buy things that we need, so I don't have to take it out of anything more fun!