I'm new in making texture packs. I make some good items, but other are very ugly xD. Can somebody tell me what resolution to use when i make an item. I will be grateful for some advises too!
Thanks in advance!
Use whatever resolution you're comfortable with, and whichever one you can make the best art with. Some people really love doing low-res pixel art while others prefer a much broader canvas with which to add intricate detail. There's no "one size fits all" answer to that question.
The best advice that I can give you, both for your initial question and in general, is to try lots of different things. Experiment with a variety of styles and resolutions to find the one that YOU want to work with.
Oh... and as another general piece of advice: do NOT look at the default textures when you're making your own. If you want reference, look at real-world objects. Minecraft textures are kinda terrible for learning art, and it's best to work from real life when you're new. That's not to say you can't stylize them or add fantasy flair, but don't worry about making things look "like Minecraft" since that'll just cripple you.