Foreword: this isn't really my original dnt steel advice. Really, it's what everyone tells anyone asking for help on this.
Ever walked in through the door to your imagination and have your mind decide that screw physics? You know, uncontrollable, erratic movement of objects, or yourself. What about getting stuck in a loop doing something, or getting stuck to things, or being afraid to move things because the world will end if you do? You're not alone. This happens to a lot of people. Most people at some point, I would venture. And most people will probably figure out some of what's below for themselves. If you're having serious problems, then here's offering the best.
Ignore it. In general, paying attention to it makes it worse. You're only worsening the situation by freaking out over it, so don't. If it's not supposed to be happening, then it isn't. Don't even tell yourself that it's not happening, because that's acknowledging that it is; you don't think about it because why would you, it isn't happening. That's the idea.
If you manage to forget about it completely, then it'll disappear completely. Of course, suddenly realising that it's not happening might start it up again, so the best thing to do is forget about it completely and never read this guide again.
Yes, it's hard to just ignore something that's causing chaos or flying you through the air at impossible speeds and whatnot, but you need to. This is the only sure-fire way to get rid of anomalies if they're problematic. If it's not working then it's your fault.
You might not like the 'ignoring it' method, or it doesn't work, or whatever. Don't panic; there are alternatives. Next on the list is laying down some ground rules. Impose the laws of physics onto your imagination. If you don't know Newton's laws then look them up; it's educational, too. If you do then make sure everything operates according to them. It should be as simple as deciding that they are operational and understanding them.
If your mindstuff defies the law, then remind it and yourself that it's not possible, and that this, therefore, cannot be happening. You can combine this technique with the one about ignoring for greater affect.
If you're going to do tulpa then you're going to have to brush up on visualisation skills at some point. You may well find that - especially if you're encountering problems near the beginning of the process - that improving your visualisation skills will help. Now, advice on how to do such a thing is plastered all over the board, so I'll leave you to it.
Seriously, it's your imagination for God's sake. People say 'wonderland', which makes it sound like a mystical far-off world where anything is possible with magic, when in reality it's just your imagination. It's your mind, and you can and should exercise control over it. You'd do well to remember that for the whole process, quite frankly.
I'm sure that's far from all the ways of dealing with this sort of thing, so if you happen to have a suggestion then do tell.