Use bids to provide your estimated price for the project and concisely describe your proposal.

Review project description and buyer's profile.
Make sure you understand the context of the project, and exactly what the buyer is requesting. You can ask for more details on the project message board.

Include focused comments.
A buyer wants someone who is interested in their project. If you have questions, keep them short and direct. If the buyer asks you questions about the project requirements (best database, most attractive web colors) or your skills (level of experience, similar projects completed) keep your answers focused. Bids that don't address project requirements are ineffective and are considered spamming.

Describe your approach.
The buyer will want to know how you handle this kind of work. For example, if the buyer needs research done, explain how you will find the requested information -- sources you might use, technology or tools you have available, etc. This gives them an idea of how you'll complete the work and indicates that you have relevant knowledge.

Include accurate pricing.
The buyer expects your bid to reflect the actual project cost as closely as possible. If the buyer hasn't provided sufficient details, ask questions on the message board or state assumptions in the bid ("this price assumes four colors in the logo"). You can place a new bid once the buyer clarifies the details. It is unprofessional to change the cost drastically upon winning the project, or place lowball bids just to get attention.

Specify revisions or drafts.
It is always a good idea to state how many revisions or drafts you will provide, even if offered as a guideline. Buyers often may not know what it takes to do the work, and this will help avoid confusion about what is included in your bid amount.

Indicate time frame and milestones.
Buyers always appreciate seeing progress. Tell them if you will have the first draft of a logo completed within one week and then the additional revisions completed two weeks after that. If the buyer has already described expected milestones, indicate whether you'll be able to meet them or not.

Upload files.
For project-specific work samples or more detailed proposals, upload files from your portfolio and attach them directly to your bid. This makes it even easier for the buyer to evaluate your work. You can also make a more detailed bid by attaching a separate document. Include spec work or mock-ups at your own risk. Elance strongly advises against free mock-ups.

Specify payment terms.
If you require up-front payment or a deposit, indicate this clearly in your bid. It's also a good idea to check buyers' feedback to see that they have paid other service providers on time. There are many reasons for delayed payments -- you may still want to bid, and adjust your terms by asking for a larger up-front payment.

Check your bid.
Review your bid closely before submitting. Once you submit your bid, you cannot edit or remove it.