As some have mentioned here already, there's strength to reasoning and logic behind any permanant decision. When I get the opportunity to ctb here are a few things that I'll put into practice prior to my attempts:
- Strong desire to ctb, along with speaking out loud the primary reason for doing so
- Remind yourself the specific thought that led you to purchasing or planning your method.
- Get all your affairs in order whatever they may be. Sometimes its hard to go back on decisions that we've made, especially if we plan to be dead before having to deal with the ramifications. Let that fear motivate you further.
- Weigh the worse case scenario vs the best case scenario of deciding not to ctb.
- Remind yourself this is the only way out of living, and the easiest way to find peace. Every attempt after this one will be more difficult.
- Regardless of the method its important to constantly tell yourself that your method does work 100% of the time, and trying to go back once you've started will leave yourself in an even worse state, and maybe even unable to ctb from then on.
Some people would argue that if you can tell yourself all those things, you absolutely need to first tell a mental health professional. Depending on your situation I also might agree with that way of thinking, its important to exhaust your options if you're on the fence.
Otherwise, this isn't perfect, but will absolutely aid against SI if you're up against a wall and need to ctb after weighting out every other option. To a lot of us failure is significantly more scary than death, and this can elongate the pain most of us find ourselves in. I'm not trying to get more people to ctb, but if you're already set and struggling against SI, some of this should help.