The structure of your bullet points should be consistent. Here are a few rules I like to adopt.
First, decide whether you will be using capitals or not. Having bullet points starting with a mixture of uppercase or lowercase words creates an impression that the slide is not finished and only in draft.
Second, try and get the first words to be consistent with respect to whether it is a verb or noun. If you start your first bullet with ‘Development of a solution…’ then use ‘Creation of a process…’ and avoid ‘Creating…’ for example.
Third, as a rule I would strongly suggest that you do not add fullstops at the end of any bullet points – or indeed a paragraph. Save you full stops for the end of a sentence within a passage of writing. The same rule should apply for colons and semi-colons too.
Whilst of course grammatically correct, the punctuation will clutter the slides and make them more difficult to read. It is worth checking the whole presentation to ensure that they have not crept in as you have assembled your work. In particular look out for them when you are copying snippets in from other documents.
If, for a style reason, you do want to include them make sure that they are used consistently throughout the presentation. Having an inconsistent approach will suggest a presentation that has been assembled by more than one person or perhaps a ‘cut and paste job’.
When adding bullets or numbering I like to create a space between the bullet/number and the first word. It makes the line easier to read and it will look better on the page. Do not just add spaces with the space bar. It’s best to learn how to use tabs and indents. There are plenty of guides on the internet just search for ‘powerpoint adding indents and tabs’ or visit the following links.