If you want to reduce the possibility of being refused DLA/IB etc, may I suggest the following:
 
1.  If you are filling in the form by yourself, make sure you provide as much information as you possibly can.  If you are not able to do that, get help.  St Luke's Advice Service (SLAS) is here to help and its trained volunteers have developed expertise in filling in DLA forms and have been successful on many occasions.

2.  If you are refused DLA, you have a one-month deadline in which to decide whether or not to appeal that refusal.  It is usually worth appealing and statistics have shown that an oral appeal is more likely to be successful than a paper hearing.  If you want me to represent you at an appeal, I need you to contact me as soon as you are informed that your application has been refused.  You should contact the DWP immediately you are refused to tell that you want an oral appeal.  The appeal form is GL24 that must be completed and it would help me if you could do that yourself and not wait to see me as I cannot always see people as quickly as I would like to, so to protect your appeal right, you must make sure that the appeal form GL24 is completed, signed and returned to the DWP within the one month time limit.

3.  You might need more than one appointment with me (or with one of the local law students helping me) as a lot of information is required from clients as I will need to produce written arguments (called submissions) that are presented to the Tribunal.  Part of the documentation that I need to organise is medical evidence so I will need to write to your GP and/or Consultant for their opinion of your medical condition and confirmation of how it affects your mobility and personal care needs.

4.  Once I have prepared your written submissions (I prefer clients to read them and agree what I have written but some clients have been too ill to read them), I will send it to the Tribunal Service (preferably 2 weeks in advance of your hearing) with the medical evidence and any other relevant evidence I have gathered on your behalf.

5.  At the appeal, I do not have to say very much because I have made all of the arguments on your behalf in your written submissions.  On the day, the Tribunal panel will want to hear from you and not me so the Tribunal will say they want to have a conversation with you to find out how your medical condition affects you.  The Tribunal will also listen to any evidence that your witnesses can give them.  DLA panels consist of three people:  a legally qualified chairman/woman; a medically qualified person; and a layperson who has experience of disability issues.
 
6.  The Tribunal usually makes its decision on the day, but sometimes appeals can be adjourned in order to obtain further medical evidence and then return at a later date.  If your appeal is successful, your DLA should be seamlessly backdated so that there is no interruption in your benefit.  It can, however, take a few weeks for any payments to be sent to you.
 
7.  The appeal process does take a long time (and about 25 hours of my time) and all my clients have found it very stressful, but please persevere as it is worth it!"