Keep "the main thing the main thing".
Don't fear change.
Learn from failure.

Bad             Good
can't           can
won't           will
mustn't         must
shall not       shall
don't have to   have to
ought to
ought not to

Russell's Decalogue
1 Do not feel absolutely certain of anything.

2 Do not think it worth while to proceed by concealing evidence, for the 
evidence is sure to come to light.

3 Never try to discourage thinking for you are sure to succeed.

4 When you meet with opposition, even if it should be from your husband or your 
children, endeavor to overcome it by argument and not by authority, for a 
victory dependent upon authority is unreal and illusory.

5 Have no respect for the authority of others, for there are always contrary 
authorities to be found.

6 Do not use power to suppress opinions you think pernicious, for if you do the 
opinions will suppress you.

7 Do not fear to be eccentric in opinion, for every opinion now accepted was 
once eccentric.

8 Find more pleasure in intelligent dissent than in passive agreement, for, if 
you value intelligence as you should, the former implies a deeper agreement 
than the latter.

9 Be scrupulously truthful, even if the truth is inconvenient, for it is more 
inconvenient when you try to conceal it.

10 Do not feel envious of the happiness of those who live in a fool's paradise, 
for only a fool will think that it is happiness.