This description of my puzzle creating process contains some spoilers. I block them out as much a I can, but I'd suggest you go do the puzzle first and then come here for some advice or just to see what I was thinking!
When creating standard 15x15 puzzles, you would usually start by thinking of themed entries. I like to have a thematic jumping-off point, so even for this mini (5x5) puzzle I started with the word "Tufts" in mind. The first big step in creating this puzzle was to find where to put that word. Putting it in the last column or row would mean I would need a word ending in U to cross through it, and this would limit my options quite a bit, so I tried out all of the other spots until landing on the second-to-last row. If you are using a software with auto-fill capabilities, I would suggest only looking to it as guidance on what word placements leave the most/best options open, but then try your best to do the fill yourself. When it comes to filling in the rest of the words in the puzzle, an important trick to remember that not only makes filling easier but solving more enjoyable as well, is to get creative and use things like pop-culture references, names, or phrases. For example, after I had filled the puzzle about halfway, I was stuck on 6-across because no English “words” seemed to fit (I checked and the autofill was stumped as well). But once I noticed that “Enola” –a term which would have barely meant anything to anybody a couple of years ago– fit perfectly, the rest of the puzzle fell into place. Some issues to watch out for when filling puzzles include not using/overusing acronyms, not using/overusing archaic/alternative spellings, not using vulgar or offensive terms, and not using terms so obscure that no one can figure them out. I actually slightly broke some of these rules here (perhaps you can take them as examples of what NOT to do when making your own puzzle): I allowed 7-across (spoor) to be a bit obscure since all of the other words crossing through it would be “gettable”, and 3-down (loofa) is a word which can be debated on spelling but it is a fun and easy enough clue (and the spelling I used is a very common one) so it should not confuse anybody. It really comes down to your judgement on the difficulty and fairness of the puzzle, and if the slight issue with one word is outweighed by the benefit of the other words it enables you to use.
Once the puzzle is filled with gettable but interesting words, it is time to write the clues, my favorite part! Clue writing can turn a puzzle full of boring common words into a creative wordplay experience. Besides just defining a word, you can use some tricky wording to mislead solvers, or use puns or alliteration just for the fun of it. You can also control the difficulty of the puzzle; for example, for 2-down (input) I could have clued it as “Enter, for data”, but that felt a bit too obvious considering there are many easy words in the puzzle already, so I instead clued it as “Something you might offer unwanted, e.g. two cents” Or as I mentioned earlier, I made sure to use “Tufts” in this puzzle, but I then decided to not clue it as Tufts the university, but as “Bunches of hair or grass” and let the solver put the reference together themselves. The words which make up the puzzle obviously matter, but in my opinion most of the fun comes from the clues, as a cool word with a difficult or boring clue ruins the experience, but the most mundane words clued in a funny way can make a solver’s day!
Thanks so much for solving my puzzle, and be sure to ask me any questions or give me any suggestions on how to improve in the comments!