Common to an appendix, annexure or schedule is that they are all “attachments“. Therefore, you should refer to “Attachment 1” and not “Appendix 1” or “Annexure 1” and make it clear from the wording in the agreement whether they are intended to be an integral part of the agreement or not.
The short answer is no. A lawyer is not required to draft a contract for a business or an individual. In fact, anyone can draft a contract. Although this is the case, it's not necessarily the best strategy.
Complete the legal document to determine where to attach the exhibit. Include a typed notation within the body of the legal document where the exhibit should be referenced. Thereafter, assign the exhibit with an identifying number or letter.
Parties' Signatures: Though not always necessary, having parties sign off on exhibits can provide additional legal certainty.
“Attachments” means any documentation, appended to a contract or incorporated by reference, which DOES NOT (emphasis given) establish a requirement for deliverables. “Exhibit” means a document, referred to in a contract, which is attached and establishes requirements for deliverables.
Proper Formatting for Exhibits Labels should be concise yet descriptive, employing a consistent format, such as “Exhibit A,” “Exhibit B,” followed by a brief descriptor. Once labeled, exhibits must be integrated seamlessly into the document.
For example, a court will never enforce a contract promoting something already against state or federal law (you can never enforce a contract for an illegal marijuana sale) or an agreement that offends the "public sensibilities" (contracts involving some sort of sexual immorality, for example).
Once all parties have agreed, the addendum should be attached to the original contract. Each party should sign and date the addendum.