The basic rule is that you can use the TM any time to indicate that you are using a word or logo (or other type of trade mark) as a trade mark, but you should only use the ® symbol if you have registered the trade mark.
Some owners choose to use an asterisk after the first reference to a trade mark and then refer to the asterisk elsewhere on the packaging to more fully refer to their trade mark protection.
It is a good idea that some form of notice appears any time a reference is made to the trade mark including on the product itself, packaging, marketing material, advertisements and accompanying manuals or guidelines.
It is also important that you ensure that the use of the trade mark is consistent, as protection only applies to the version of the trade mark that is registered. Variations are not necessarily protected.
Wilson Gunn can advise on all aspects of intellectual property protection. Please get in touch to speak to a member of our team about trade mark protection.