Make sure you have enough of all your reagents before you start.
Find the literature procedure that is the most similar to your system.
If starting material is not precious, try it on a 1 mmol/ 250 mg scale.
If starting material is precious, try it on the smallest scale you feel confident running, or on 1/4 or 1/3 of the material available.
Start it in the morning so you can monitor it all day- note exactly how long it takes.
Be vigilant about stirring, addition rates, and temperature control. You can control these variables, make sure you do!
Write color changes, solution behavior, TLC and purification conditions, and a detailed reaction procedure in your notebook. If something goes wrong during the experiment, note ideas for ways to avoid the problem the next time.
Isolate and try to identify (i.e. get an NMR) of EVERY product formed.
If you get your desired product: Note any acid-sensitivity over time (silica gel or CDCl 3 ), volatility (high vacuum), and thermal stability over time (sitting on bench or in NMR tube).