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Just going to "chime" in here.
First up collimation via star test should always be done with the focus racked out. Not in. Out of focus collimation is the most accurate method.
Next, forget Cheshires etc. Not sure how many times I have to repeat this but a Cheshire is not useful at all for collimating an RC. The figure of the two mirrors is such that it demands a very high degree of collimation to produce sharp images. I have a Howie Glatter laser for an RC and even that gives very inaccurate results. I have tried all the methods suggested and only one works every single time. It is hard to perfect it but it works! You can get very good collimation in only minutes, but perfection needs careful attention to detail. Search my posts on the matter and how to collimate using a Tak scope.
The best method for collimating an RC by far is a Takahashi collimation scope. It you own an RC or BRC these scopes are a must. It will give you an accurate collimation, so much so you will not need to do a final star test, if you are very particular. I have done collimation it so often with working on GSO RC's I could almost do it blind folded. I have owned GSO RC scopes since they first came to Australia. I have had several RC's in pieces and built them back together, and collimated each and everyone of them to a high standard. If you own a folded scope sooner or later you have to clean the mirror and then you will need to touch the primary adjustment screws anyway. You cannot do a full collimation with these scopes without touching the rear screws. So advice saying that not to touch them is not useful. Owning a folded scope that has primary collimation screws means inevitably you will need to adjust those screws. Fast Newtonians are the same and require adjusting of the rear collimation screws from time to time. Transit from Taiwan to Australia will upset the collimation and sure as eggs you need to collimate the scope.
That said, if you want to go and try the other methods, feel free to knock yourself out.
Jumping in the deep end and doing a full collimation will help you learn. If you get stuck and cannot get the scope back into properly collimation after trying, you can send it to me and I will collimate it and send it back. I will charge you for the return freight only. However, I doubt that you will need to do this. Collimation sounds daunting but everyone starts from the same position and has to learn.
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