Mme Sra is either not available or she is working on your text.

You write very well, despite a few grammatical and syntax errors many of which you could probably avoid.

To get you started, I enclose a few to help you with self corrections. Do look for other similar ones, in addition to syntax errors, which I will leave to Mme Sra, who does a much better job than I can.

Some of the things to watch out:
agreement in number between subject and verb, and between nouns and adjectives.

Also watch out the use between qui and que. The former acts as a subject (je, tu,...), and the latter as an object (me, te,...).

Usually if you write a long text, leave it aside for a day, and reread it, you will most likely find some corrections/mistakes.

Félicitations et bon travail!

Here are some of the corrections you could do:
Nous avons (décorér) nos Noël
Mes frères et soeur (faites)
ils (créés)
sont très brillant( ) et élégant( )
(garland) brillant( ) => guirlande (n.f.)
l'étoile (big) que nous (vient) d'acheter
(sur notre arbre de Noël) should follow ..."de placer"
Les ornements qu(i) j'aime : que
sont musicale( )
Je souhai(t)

To improve your writing skills and reduce grammatical and syntax errors, here are a few tips:

1. Review subject-verb agreement: Make sure the verb matches the subject in both number and person. For example, instead of "Mes frères et soeur (faites)," it should be "Mes frères et sœurs faisaient."

2. Pay attention to noun-adjective agreement: Ensure that adjectives agree in gender and number with the noun they modify. In the sentence "ils (créés) sont très brillant( ) et élégant( )," it should be "ils sont très brillants et élégants."

3. Understand the difference between "qui" and "que": "Qui" is used as a subject pronoun (who) while "que" is used as an object pronoun (whom/that). For instance, in the phrase "Les ornements qu(i) j'aime," "qui" is incorrect, and it should be "que."

4. Take time to proofread: After writing a longer text, it's beneficial to set it aside for a day or at least a few hours and then reread it. This break allows you to approach the text with fresh eyes and often helps you spot mistakes or areas for improvement.

5. Seek help from language experts: If available, enlist the assistance of language teachers, tutors, or native speakers to review and offer guidance on grammatical and syntactical errors. Their expertise can be invaluable in helping you improve your writing.

Remember, practice makes perfect, so keep writing and seeking feedback to further enhance your skills. Good luck!

To improve your writing, here are the suggested corrections:

1. "Nous avons (décoré) nos Noël" - (decorated).
2. "Messieurs frères et sœurs (ont fait)" - (brothers and sisters have made).
3. "Ils (ont créé)" - (they have created).
4. "(Elles) sont très brillant(es) et élégant(es)" - (They are very bright and elegant) - change the adjectives to agree with the plural subject.
5. "(Une guirlande) brillante" - (bright garland) - replace " ( )" with the correct phrase.
6. "L'étoile (grande) que nous venons d'acheter" - (The (big) star that we just bought) - add the correct adjective and use "venons" to agree with "nous".
7. "(Pour placer) sur notre arbre de Noël" - (to place) - rephrase to indicate the purpose.
8. "Les ornements que j'aime :" - (The ornaments that I like) - use "que" to indicate the object.
9. "(Sont musicaux)" - (are musical) - add the correct adjective to agree with the plural subject.
10. "Je souhait(e)" - (I wish) - use the correct verb form.

With these corrections, your text will be more accurate and grammatically correct.