How best can I practice to get better at the combat in Terraria?

[WaywardZeppelin]

I've played for over 1000 hours in total over several years and somehow I still suck at combat, any advice? Anything (except the phrase "get good" or similar) can help, even advice you'd give to people who just started.

[Zereph]

I havent played as many hours as you (around 500), but when i first started playing, I was using the summoner class, which I was a glass cannon and was forced to learn how to dodge bosses as I progressed through the game. I also found it way easier with the camera zoomed in a bit at the start as I could see what I was doing, but as I got better at the game and I learnt boss patterns and how to dodge attacks, I zoomed the camera out a bit more as I was unable to see certain attacks as easily (eg the empress). I also rebound some of my controls and have my quick heal shortcut set as F, my map is my mouse scroll button pressed in, my different combat style loadouts are set as Z,X,C, my wings are set as e, my hook is q, my left side buttons on my mouse are my 1st and 2nd hotbar (Zenith/Rod of Harmony). Its all personal preference though. As funny as it sounds, alot of my skills with how I approach bosses and adapting to them came from my time spent playing souls games. I think the best way to learn how to fight a boss (without cheating one in) is to create/obtain a whole bunch of the boss summoning item so you can jump right back in to fighting the same boss again after dying. A rod of harmony is also extremely useful too (especially stalling bosses while you regen/wait out potions or even dodging attacks). Soaring insignia and celestial starboard are also very good for dodging bosses without using an arena. Locking the hotbar (the lock button in the top left corner when you press esc) and favouriting items in your inventory you want to keep (alt left click) also makes combat way less annoying. Using the correct accessories, weapons, armour and enchantments make a huge difference too.

[Xaelon]

The least annoying way to practice specific boss fights in this game would be play in Journey Mode.

Then you can adjust the difficulty, freeze time and do pretty much whatever else you want. Just dupe a bunch of boss summon items and you can try the fights as many times as you want with no waiting.

You could also turn on godmode and focus on learning how to dodge each boss's attacks.

That's pretty much it. Just do the fights over and over and over until you're comfortable with them. Then you can start a non-journey mode run on Normal difficulty and work your way up from there.