Arbitrarily raise the bar of acceptable proof for alternative theories, while lowering it for mainstream ones.
Systematically employ double standards of evidence required to prove an hypothesis/theory.
When it comes to alternative explainations, treat the absence of definitive proof as a definitive disproof. If your opponents cannot prove their case with 100% mathematical certainty, or give a 100% complete explaination (in other words: always, because such level of perfection cannot exist in science), use this as an excuse to dismiss in block all presented evidence as if no evidence was presented at all, and as a justification to refuse doing any further inquiry on the subject.
Use the exact opposite strategy when it comes to your explaination: treat the absence of definitive disproof as a definitive proof. if you can come up with any remotely plausible explaination for a problem, than automatically treat that explaination as the necessarily correct one, and the problem as "solved"; since such weak retorts can be made on almost any issue, this will allow you to "explain" every problem with your theory with little effort, and save it from rejection.
In order for this trick to work is important to always treat every problem in isolation, in order to avoid a comparative pro/cons analysis that might show the alternative as clearly superior in light of Ockham's Razor.