Using BeamerBeamer is a great $\LaTeX$ standard, allowing automation of bad talks.

• try to maximize the total number of slides, in particular avoid the rule of 2 minutes per slide, and do not hesitate to use hundreds of slides for a one hour talk;
• try to use as much sections and subsections as possible;
• try to maximize the total number of words and formulas is each slide;
• never use the telegraphic style, write complete sentences everywhere;
• write exactly what you will say and say exactly what you wrote;
• use lots of \pause in your slides to make sure people follow exactly what you are saying word by word, and do not start to think about what you claimed 20 seconds ago;
• possibly put just one sentence per slide, to make sure you often have to change: people will have no way of remembering what was just written in the previous ones;
• you may also prepare once and for all 100 slides and then just select some at random depending on the length of your talk;
• put lots of colors, in particular those which will never be rendered correctly on a beamer;
• avoid intuitive and structural explanations, focus as soon as possible on technical aspects showing your technical skills;
• never spend time in presentation of the domain and context, this is useless;
• never spend time on the interpretation of your graphics;
• put tiny pictures with an embedded legend that nobody will ever be able to read;
• use nice pictures and do not worry about their origin (probably from Google anyway);
• forget to cite the ground-breaking results of your colleagues in the room;
• keep in mind that aesthetics is useless, superficial, a waste of time;
• never take into account the background of your public;
• never take into account how other people give talks;
• never watch yourself on video giving a talk.

Using the blackboard.

• write as small as possible;
• change as much as possible your notations;
• use abbreviations, and never hesitate to avoid standards;
• always erase the part of the blackboard that you have just used;
• never use the blackboard linearly;
• never think about the way you will use the blackboard before your talk;
• the best is to avoid written notes, and to avoid to prepare the talk;
• never speak loudly, and never face the public;
• never use your hands when speaking, this is a silly Latin habit;
• pick other good ideas in the Beamer list above: never spend time on intuition or structure, go straight to the technical side, etc.

Further material.

Credit. This post was written in collaboration with my colleague Mathieu Lewin.