LinkedIn is the leading social platform in professional networking and marketing. It has helped bridge gaps with many recruiters and clients/candidates, allowing an informal, formal approach in communication. Although this is well known, many find it difficult to or don't really understand how to market themselves correctly on the popular platform.
The way your profile is displayed is very important. This isn't layout as such, as LinkedIn doesn't allow much personalisation to the design of your profile, but the content and use of wording is essential. A professional and friendly picture is a good way of representing personality, yet professionalism. Your strapline should be kept concise, inluding your job title and speciality, making it easier for potential employers to find you, and understand your skills immediately.
Identifying companies and employees within your chosen industry and sending a connection request to their Senior Level employees (MD/CEO etc.) exposes yourself to them, and encourages chances of building a bridge in future employment opportunities. Don't be afraid to send connection requests, it is a networking site and people expect it.
Once you're connected, you should edit your standard connection note, making it more personal - have them some saved which you can paste in when needed, depending on the sector/industry/role you're looking to entice. Be aware there is a limitation on characters, so keep it concise.
Never be hesitant to send follow up messages, without bombarding, just explain what you can offer, then try to arrange a call to discuss things further. 3rd Degree connections will need an InMail, so the best option is to build your 1st Degree connections, allowing you to open up more to 2nd Degree connections.
You should be treating your profile as a sales strategy, with yourself being the product, let people know why you would be worth the connection.