A guide is when you provide enough information for the user to be able to go from step A to step B by solely following your guide. Tips & tricks is when you simply give pointers on useful activities. Here's an example;
Tips: When getting 99 herblore you should get a herb sack. It becomes much easier to level up.
Guide: You can get a herb sack from the vote shop. It is useful for collecting herbs from potential PvM drops, allowing you to stack on herbs while saving up inventory space. However, collecting herbs from Farming is more beneficial as you can collect one specific herb in high quantities compared to getting random herbs in low quantities as drops.
TL:DR: A guide has many more instructions and clear details. Tips & tricks is the same as saying "Do this, do that and that's it".