Best tips for practice?

[Falc01]

Okay, so I'm gonna enter a tournament this month and I want to get some good practice in.
I would say I'm an above average player, but I don't really have a solid way to practice.
The thing is that I usually play online and think that I do fine, but once I play offline I notice that I need to get used to there being no input delay wich is a problem.
I usually play snake and joker and do pretty decent with them online, but then once I play offline (wich I can do about once a week max since my friends are usually busy) I perform way worse cause of my online bad habits.
Now people have recommended for me to get a Lan cable but that's unfortunately no option for me. I can only play on wifi wich can be good at times, but is unfortunately, inconsistent.
Any help on how I can practice properly instead of playing online on wifi?

 

[KoyPond]

The best way that I have found to practice is give yourself a handicap (Example: Launch easier, Start with damage...) Then you will have to review your own strategies and find flaws them. This also lets you see your bad habits (Example: Rolling into people, grabbing early or late...). Practice against lvl 9 works well too. Hope this helps. Also good luck on the tournament.