Check licensing requirements for your profession.
Make sure that you have all relevant original documents for your profession. Bring them in your hand luggage when you make Aliyah (suitcases can go missing and shipments may be delayed).
Contact an Israeli notary in order to arrange notarised translations of documents (if necessary).
Doctors with a specialisation - contact the Scientific council in order to have your specialty recognised.
Be in contact with appropriate professionals and / or licensing bodies to receive get updates regarding licensing exam dates.
When possible, apply to be examined as quickly as possible.
Build a list of contacts in your field prior to aliyah. Be in contact with them close to your date of Aliyah so that you can hit the ground running.
Prepare a resume / CV - if possible in Hebrew as well as English.